687815972225 has 6 divisors (see below), whose sum is σ = 852891805590. Its totient is φ = 550252777760.

The previous prime is 687815972191. The next prime is 687815972251. The reversal of 687815972225 is 522279518786.

It can be written as a sum of positive squares in 3 ways, for example, as 1289384464 + 686526587761 = 35908^2 + 828569^2 .

It is not a de Polignac number, because 687815972225 - 2³⁰ = 686742230401 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 13756319420 + ... + 13756319469.

It is an arithmetic number, because the mean of its divisors is an integer number (142148634265).

Almost surely, 2^687815972225 is an apocalyptic number.

It is an amenable number.

687815972225 is a deficient number, since it is larger than the sum of its proper divisors (165075833365).

687815972225 is a wasteful number, since it uses less digits than its factorization.

687815972225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27512638899 (or 27512638894 counting only the distinct ones).

The product of its digits is 33868800, while the sum is 62.

The spelling of 687815972225 in words is "six hundred eighty-seven billion, eight hundred fifteen million, nine hundred seventy-two thousand, two hundred twenty-five".