640581264187038 has 24 divisors (see below), whose sum is σ = 1407474326948976. Its totient is φ = 210519664286400.

The previous prime is 640581264187031. The next prime is 640581264187049. The reversal of 640581264187038 is 830781462185046.

640581264187038 is a `hidden beast` number, since 6 + 4 + 0 + 581 + 2 + 6 + 4 + 18 + 7 + 0 + 38 = 666.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640581264187031) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 250618646683 + ... + 250618649238.

It is an arithmetic number, because the mean of its divisors is an integer number (58644763622874).

Almost surely, 2^{640581264187038} is an apocalyptic number.

640581264187038 is an abundant number, since it is smaller than the sum of its proper divisors (766893062761938).

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

640581264187038 is a wasteful number, since it uses less digits than its factorization.

640581264187038 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 501237296000 (or 501237295997 counting only the distinct ones).

The product of its (nonzero) digits is 61931520, while the sum is 63.

The spelling of 640581264187038 in words is "six hundred forty trillion, five hundred eighty-one billion, two hundred sixty-four million, one hundred eighty-seven thousand, thirty-eight".