640692535 has 16 divisors (see below), whose sum is σ = 880771392. Its totient is φ = 438278400.

The previous prime is 640692523. The next prime is 640692539. The reversal of 640692535 is 535296046.

It is not a de Polignac number, because 640692535 - 2²⁹ = 103821623 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640692539) 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 15 ways as a sum of consecutive naturals, for example, 7006 + ... + 36475.

It is an arithmetic number, because the mean of its divisors is an integer number (55048212).

Almost surely, 2^640692535 is an apocalyptic number.

640692535 is a deficient number, since it is larger than the sum of its proper divisors (240078857).

640692535 is a wasteful number, since it uses less digits than its factorization.

640692535 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43914.

The product of its (nonzero) digits is 194400, while the sum is 40.

The square root of 640692535 is about 25311.9050053527. The cubic root of 640692535 is about 862.0846017599.

The spelling of 640692535 in words is "six hundred forty million, six hundred ninety-two thousand, five hundred thirty-five".