636554861660 has 24 divisors (see below), whose sum is σ = 1336780653936. Its totient is φ = 254619002880.

The previous prime is 636554861639. The next prime is 636554861711. The reversal of 636554861660 is 66168455636.

It is a happy number.

It is a Smith number, since the sum of its digits (56) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 636554861596 and 636554861605.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2673695 + ... + 2902025.

It is an arithmetic number, because the mean of its divisors is an integer number (55699193914).

Almost surely, 2^636554861660 is an apocalyptic number.

It is an amenable number.

636554861660 is an abundant number, since it is smaller than the sum of its proper divisors (700225792276).

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

636554861660 is a wasteful number, since it uses less digits than its factorization.

636554861660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 367733 (or 367731 counting only the distinct ones).

The product of its (nonzero) digits is 18662400, while the sum is 56.

The spelling of 636554861660 in words is "six hundred thirty-six billion, five hundred fifty-four million, eight hundred sixty-one thousand, six hundred sixty".