687979008025 has 27 divisors (see below), whose sum is σ = 900459927423. Its totient is φ = 521355949200.

The previous prime is 687979008023. The next prime is 687979008077. The reversal of 687979008025 is 520800979786.

The square root of 687979008025 is 829445.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 247672442889 + 440306565136 = 497667^2 + 663556^2 .

It is not a de Polignac number, because 687979008025 - 2¹ = 687979008023 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (687979008023) 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 26 ways as a sum of consecutive naturals, for example, 78792910 + ... + 78801640.

Almost surely, 2^687979008025 is an apocalyptic number.

687979008025 is the 829445-th square number.

687979008025 is the 414723-rd centered octagonal number.

It is an amenable number.

687979008025 is a deficient number, since it is larger than the sum of its proper divisors (212480919398).

687979008025 is an frugal number, since it uses more digits than its factorization.

687979008025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17510 (or 8755 counting only the distinct ones).

The product of its (nonzero) digits is 15240960, while the sum is 61.

The spelling of 687979008025 in words is "six hundred eighty-seven billion, nine hundred seventy-nine million, eight thousand, twenty-five".