Millennials aren't the defining factor in Bank of America's mobile banking strength, which grew by 11 percent in the second quarter to 25.3 million active users, Chairman and CEO Brian Moynihan told CNBC on Monday.

"Our mobile capabilities and core mobile banking go far beyond the millennials," Moynihan told "Mad Money" host Jim Cramer in an exclusive interview after earnings.

"I got asked a question on the earnings call today, ‘Is this millennials?’" the CEO said. "Well, there’s 35 million digital users. There aren’t enough millennials to do that. And so it spreads across all age cohorts, even guys as old as us, Jim."

Bank of America reported fiscal second-quarter earnings before Monday's opening bell. The country's second-largest lender saw profit climb 33 percent to $6.8 billion, trouncing Wall Street estimates of $5.92 billion.

The profit bump was buttressed by higher-than-expected cost-cutting, with expenses down 5 percent year-over-year, totaling $13.3 billion. The bank's earnings per share also topped analysts' expectations.

Digital usage continued to grow this quarter, boosted by 1.4 billion logins to Bank of America's mobile app and 35 million peer-to-peer payments in the Zelle app, the big banks' answer to PayPal's Venmo.

In Bank of America's business, digitization "means better convenience for the customer and lower operating cost for us and more assured transactions, more straight-through processing," Moynihan said.

"It enables the process to work better, and all that produces a good result for the customer," he told Cramer. "Our customer service scores continue to go up, while at the same time the cost structure, in the consumer bank especially, continues to come down."

Management highlighted the bank's positive operating leverage — increased profit as a result of lower costs and higher gross margins — as a reason for the better-than-expected results, saying that this was the 14th straight quarter in which Bank of America delivered higher operating leverage.

Bank of America's stock traded higher on Monday, rising more than 4 percent and closing at $29.78 a share. Most analysts issued positive notes after the report, with Morgan Stanley, Wells Fargo and J.P. Morgan giving the stock "overweight" ratings.

In May, Bank of America's head of digital banking told Cramer that the rise of digital peer-to-peer payment services in banking could pave the way to a new, cashless reality.