640585542638 has 16 divisors (see below), whose sum is σ = 987596327520. Its totient is φ = 311399895456.

The previous prime is 640585542617. The next prime is 640585542671. The reversal of 640585542638 is 836245585046.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3183881 + ... + 3379092.

It is an arithmetic number, because the mean of its divisors is an integer number (61724770470).

Almost surely, 2^640585542638 is an apocalyptic number.

640585542638 is a deficient number, since it is larger than the sum of its proper divisors (347010784882).

640585542638 is a wasteful number, since it uses less digits than its factorization.

640585542638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6564331.

The product of its (nonzero) digits is 27648000, while the sum is 56.

The spelling of 640585542638 in words is "six hundred forty billion, five hundred eighty-five million, five hundred forty-two thousand, six hundred thirty-eight".