640105767 has 24 divisors (see below), whose sum is σ = 1103132400. Its totient is φ = 365773968.

The previous prime is 640105759. The next prime is 640105819. The reversal of 640105767 is 767501046.

640105767 is a `hidden beast` number, since 640 + 1 + 0 + 5 + 7 + 6 + 7 = 666.

It is not a de Polignac number, because 640105767 - 2³ = 640105759 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640105747) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 240592 + ... + 243237.

It is an arithmetic number, because the mean of its divisors is an integer number (45963850).

Almost surely, 2^640105767 is an apocalyptic number.

640105767 is a deficient number, since it is larger than the sum of its proper divisors (463026633).

640105767 is a wasteful number, since it uses less digits than its factorization.

640105767 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 483852 (or 483839 counting only the distinct ones).

The product of its (nonzero) digits is 35280, while the sum is 36.

The square root of 640105767 is about 25300.3115988717. The cubic root of 640105767 is about 861.8213459174.

The spelling of 640105767 in words is "six hundred forty million, one hundred five thousand, seven hundred sixty-seven".