640087787550 has 48 divisors (see below), whose sum is σ = 1587566282112. Its totient is φ = 170674101600.

The previous prime is 640087787491. The next prime is 640087787593. The reversal of 640087787550 is 55787780046.

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, 1453855 + ... + 1842245.

It is an arithmetic number, because the mean of its divisors is an integer number (33074297544).

Almost surely, 2^640087787550 is an apocalyptic number.

640087787550 is an abundant number, since it is smaller than the sum of its proper divisors (947478494562).

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

640087787550 is a wasteful number, since it uses less digits than its factorization.

640087787550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 399393 (or 399388 counting only the distinct ones).

The product of its (nonzero) digits is 13171200, while the sum is 57.

The spelling of 640087787550 in words is "six hundred forty billion, eighty-seven million, seven hundred eighty-seven thousand, five hundred fifty".