125515521 has 16 divisors (see below), whose sum is σ = 189907200. Its totient is φ = 81895824.

The previous prime is 125515519. The next prime is 125515553.

125515521 is a `hidden beast` number, since 125 + 5 + 15 + 521 = 666.

125515521 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 125515521 - 2¹ = 125515519 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (125515561) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48186 + ... + 50723.

It is an arithmetic number, because the mean of its divisors is an integer number (11869200).

Almost surely, 2^125515521 is an apocalyptic number.

It is an amenable number.

125515521 is a deficient number, since it is larger than the sum of its proper divisors (64391679).

125515521 is an equidigital number, since it uses as much as digits as its factorization.

125515521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98965 (or 98959 counting only the distinct ones).

The product of its digits is 2500, while the sum is 27.

The square root of 125515521 is about 11203.3709659191. The cubic root of 125515521 is about 500.6864185612.

The spelling of 125515521 in words is "one hundred twenty-five million, five hundred fifteen thousand, five hundred twenty-one".