636943306940 has 24 divisors (see below), whose sum is σ = 1355903974320. Its totient is φ = 251287221888.

The previous prime is 636943306921. The next prime is 636943307027. The reversal of 636943306940 is 49603349636.

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, 218129810 + ... + 218132729.

It is an arithmetic number, because the mean of its divisors is an integer number (56495998930).

Almost surely, 2^636943306940 is an apocalyptic number.

It is an amenable number.

636943306940 is an abundant number, since it is smaller than the sum of its proper divisors (718960667380).

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

636943306940 is a wasteful number, since it uses less digits than its factorization.

636943306940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 436262621 (or 436262619 counting only the distinct ones).

The product of its (nonzero) digits is 7558272, while the sum is 53.

The spelling of 636943306940 in words is "six hundred thirty-six billion, nine hundred forty-three million, three hundred six thousand, nine hundred forty".