125115521 has 4 divisors (see below), whose sum is σ = 126222852. Its totient is φ = 124008192.

The previous prime is 125115517. The next prime is 125115527. The reversal of 125115521 is 125511521.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4906225 + 120209296 = 2215^2 + 10964^2 .

It is a cyclic number.

It is not a de Polignac number, because 125115521 - 2² = 125115517 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (125115527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 553496 + ... + 553721.

It is an arithmetic number, because the mean of its divisors is an integer number (31555713).

Almost surely, 2^125115521 is an apocalyptic number.

It is an amenable number.

125115521 is a deficient number, since it is larger than the sum of its proper divisors (1107331).

125115521 is a wasteful number, since it uses less digits than its factorization.

125115521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1107330.

The product of its digits is 500, while the sum is 23.

The square root of 125115521 is about 11185.5049506046. The cubic root of 125115521 is about 500.1539805751.

The spelling of 125115521 in words is "one hundred twenty-five million, one hundred fifteen thousand, five hundred twenty-one".