649971657 has 12 divisors (see below), whose sum is σ = 939999424. Its totient is φ = 432783000.

The previous prime is 649971643. The next prime is 649971661. The reversal of 649971657 is 756179946.

It is not a de Polignac number, because 649971657 - 2¹¹ = 649969609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (649972657) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 36469 + ... + 51282.

Almost surely, 2^649971657 is an apocalyptic number.

It is an amenable number.

649971657 is a deficient number, since it is larger than the sum of its proper divisors (290027767).

649971657 is a wasteful number, since it uses less digits than its factorization.

649971657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88580 (or 88577 counting only the distinct ones).

The product of its digits is 2857680, while the sum is 54.

The square root of 649971657 is about 25494.5417099425. The cubic root of 649971657 is about 866.2265144836.

The spelling of 649971657 in words is "six hundred forty-nine million, nine hundred seventy-one thousand, six hundred fifty-seven".