636506556772 has 6 divisors (see below), whose sum is σ = 1113886474358. Its totient is φ = 318253278384.

The previous prime is 636506556769. The next prime is 636506556799. The reversal of 636506556772 is 277655605636.

It can be written as a sum of positive squares in only one way, i.e., 601890465856 + 34616090916 = 775816^2 + 186054^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79563319593 + ... + 79563319600.

Almost surely, 2^636506556772 is an apocalyptic number.

It is an amenable number.

636506556772 is a deficient number, since it is larger than the sum of its proper divisors (477379917586).

636506556772 is a wasteful number, since it uses less digits than its factorization.

636506556772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159126639197 (or 159126639195 counting only the distinct ones).

The product of its (nonzero) digits is 47628000, while the sum is 58.

The spelling of 636506556772 in words is "six hundred thirty-six billion, five hundred six million, five hundred fifty-six thousand, seven hundred seventy-two".