640503434731 has 2 divisors, whose sum is σ = 640503434732. Its totient is φ = 640503434730.

The previous prime is 640503434723. The next prime is 640503434743. The reversal of 640503434731 is 137434305046.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 640503434731 - 2³ = 640503434723 is a prime.

It is a super-2 number, since 2×640503434731² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (640503434771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320251717365 + 320251717366.

It is an arithmetic number, because the mean of its divisors is an integer number (320251717366).

Almost surely, 2^640503434731 is an apocalyptic number.

640503434731 is a deficient number, since it is larger than the sum of its proper divisors (1).

640503434731 is an equidigital number, since it uses as much as digits as its factorization.

640503434731 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 362880, while the sum is 40.

Adding to 640503434731 its reverse (137434305046), we get a palindrome (777937739777).

The spelling of 640503434731 in words is "six hundred forty billion, five hundred three million, four hundred thirty-four thousand, seven hundred thirty-one".