125686521 has 27 divisors (see below), whose sum is σ = 188452173. Its totient is φ = 80719200.

The previous prime is 125686481. The next prime is 125686531.

The square root of 125686521 is 11211.

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

125686521 is a `hidden beast` number, since 1 + 2 + 56 + 86 + 521 = 666.

125686521 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 4 ways, for example, as 93605625 + 32080896 = 9675^2 + 5664^2 .

It is not a de Polignac number, because 125686521 - 2²³ = 117297913 is a prime.

It is a super-2 number, since 2×125686521² = 31594203122166882, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (125686531) by changing a digit.

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 in 26 ways as a sum of consecutive naturals, for example, 1244371 + ... + 1244471.

Almost surely, 2^125686521 is an apocalyptic number.

125686521 is the 11211-st square number.

125686521 is the 5606-th centered octagonal number.

It is an amenable number.

125686521 is a deficient number, since it is larger than the sum of its proper divisors (62765652).

125686521 is an equidigital number, since it uses as much as digits as its factorization.

125686521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 282 (or 141 counting only the distinct ones).

The product of its digits is 28800, while the sum is 36.

The cubic root of 125686521 is about 500.9136906551.

Multiplying 125686521 by its sum of digits (36), we get a square (4524714756 = 67266²).

The spelling of 125686521 in words is "one hundred twenty-five million, six hundred eighty-six thousand, five hundred twenty-one".