125021535021 has 20 divisors (see below), whose sum is σ = 189822220764. Its totient is φ = 81981331200.

The previous prime is 125021535017. The next prime is 125021535049. The reversal of 125021535021 is 120535120521.

125021535021 is a `hidden beast` number, since 1 + 2 + 5 + 0 + 2 + 153 + 502 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 41188702500 + 83832832521 = 202950^2 + 289539^2 .

It is not a de Polignac number, because 125021535021 - 2² = 125021535017 is a prime.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125021535421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 12646500 + ... + 12656381.

Almost surely, 2^125021535021 is an apocalyptic number.

It is an amenable number.

125021535021 is a deficient number, since it is larger than the sum of its proper divisors (64800685743).

125021535021 is an equidigital number, since it uses as much as digits as its factorization.

125021535021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25302954 (or 25302945 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 27.

Adding to 125021535021 its reverse (120535120521), we get a palindrome (245556655542).

The spelling of 125021535021 in words is "one hundred twenty-five billion, twenty-one million, five hundred thirty-five thousand, twenty-one".