640505331654 has 48 divisors (see below), whose sum is σ = 1356079872000. Its totient is φ = 201633960528.

The previous prime is 640505331637. The next prime is 640505331671. The reversal of 640505331654 is 456133505046.

It is an interprime number because it is at equal distance from previous prime (640505331637) and next prime (640505331671).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1026454 + ... + 1527945.

It is an arithmetic number, because the mean of its divisors is an integer number (28251664000).

Almost surely, 2^640505331654 is an apocalyptic number.

640505331654 is an abundant number, since it is smaller than the sum of its proper divisors (715574540346).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640505331654 is a wasteful number, since it uses less digits than its factorization.

640505331654 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2554529 (or 2554506 counting only the distinct ones).

The product of its (nonzero) digits is 648000, while the sum is 42.

The spelling of 640505331654 in words is "six hundred forty billion, five hundred five million, three hundred thirty-one thousand, six hundred fifty-four".