640975701 has 12 divisors (see below), whose sum is σ = 907865312. Its totient is φ = 402180288.

The previous prime is 640975681. The next prime is 640975703. The reversal of 640975701 is 107579046.

It is not a de Polignac number, because 640975701 - 2⁶ = 640975637 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 640975701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640975703) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 368785 + ... + 370518.

Almost surely, 2^640975701 is an apocalyptic number.

It is an amenable number.

640975701 is a deficient number, since it is larger than the sum of its proper divisors (266889611).

640975701 is a wasteful number, since it uses less digits than its factorization.

640975701 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 739340 (or 739323 counting only the distinct ones).

The product of its (nonzero) digits is 52920, while the sum is 39.

The square root of 640975701 is about 25317.4979213982. The cubic root of 640975701 is about 862.2115878364.

The spelling of 640975701 in words is "six hundred forty million, nine hundred seventy-five thousand, seven hundred one".