640700007 has 16 divisors (see below), whose sum is σ = 899848320. Its totient is φ = 404373600.

The previous prime is 640700003. The next prime is 640700041. The reversal of 640700007 is 700007046.

It is not a de Polignac number, because 640700007 - 2² = 640700003 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 640700007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640700003) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 107157 + ... + 112977.

It is an arithmetic number, because the mean of its divisors is an integer number (56240520).

Almost surely, 2^640700007 is an apocalyptic number.

640700007 is a deficient number, since it is larger than the sum of its proper divisors (259148313).

640700007 is a wasteful number, since it uses less digits than its factorization.

640700007 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7774.

The product of its (nonzero) digits is 1176, while the sum is 24.

The square root of 640700007 is about 25312.0526034536. The cubic root of 640700007 is about 862.0879530663.

The spelling of 640700007 in words is "six hundred forty million, seven hundred thousand, seven".