636637478725 has 12 divisors (see below), whose sum is σ = 789464453184. Its totient is φ = 509288060720.

The previous prime is 636637478683. The next prime is 636637478749. The reversal of 636637478725 is 527874736636.

It is not a de Polignac number, because 636637478725 - 2¹⁷ = 636637347653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 57492 + ... + 1129858.

It is an arithmetic number, because the mean of its divisors is an integer number (65788704432).

Almost surely, 2^636637478725 is an apocalyptic number.

It is an amenable number.

636637478725 is a deficient number, since it is larger than the sum of its proper divisors (152826974459).

636637478725 is a wasteful number, since it uses less digits than its factorization.

636637478725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1096124 (or 1096119 counting only the distinct ones).

The product of its digits is 213373440, while the sum is 64.

The spelling of 636637478725 in words is "six hundred thirty-six billion, six hundred thirty-seven million, four hundred seventy-eight thousand, seven hundred twenty-five".