640718873431 has 64 divisors (see below), whose sum is σ = 811637342208. Its totient is φ = 492266533248.

The previous prime is 640718873407. The next prime is 640718873441. The reversal of 640718873431 is 134378817046.

640718873431 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 640718873431 - 2³¹ = 638571389783 is a prime.

It is a super-2 number, since 2×640718873431² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640718873441) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 722343270 + ... + 722344156.

It is an arithmetic number, because the mean of its divisors is an integer number (12681833472).

Almost surely, 2^640718873431 is an apocalyptic number.

640718873431 is a deficient number, since it is larger than the sum of its proper divisors (170918468777).

640718873431 is a wasteful number, since it uses less digits than its factorization.

640718873431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1820.

The product of its (nonzero) digits is 2709504, while the sum is 52.

The spelling of 640718873431 in words is "six hundred forty billion, seven hundred eighteen million, eight hundred seventy-three thousand, four hundred thirty-one".