636660939 has 4 divisors (see below), whose sum is σ = 848881256. Its totient is φ = 424440624.

The previous prime is 636660901. The next prime is 636660943. The reversal of 636660939 is 939066636.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 636660939 - 2¹⁷ = 636529867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (636660989) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 106110154 + ... + 106110159.

It is an arithmetic number, because the mean of its divisors is an integer number (212220314).

Almost surely, 2^636660939 is an apocalyptic number.

636660939 is a deficient number, since it is larger than the sum of its proper divisors (212220317).

636660939 is a wasteful number, since it uses less digits than its factorization.

636660939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212220316.

The product of its (nonzero) digits is 944784, while the sum is 48.

The square root of 636660939 is about 25232.1409912041. The cubic root of 636660939 is about 860.2725560302.

The spelling of 636660939 in words is "six hundred thirty-six million, six hundred sixty thousand, nine hundred thirty-nine".