125534215521 has 72 divisors (see below), whose sum is σ = 214694434656. Its totient is φ = 70066264320.

The previous prime is 125534215519. The next prime is 125534215613. The reversal of 125534215521 is 125512435521.

125534215521 is a `hidden beast` number, since 1 + 2 + 55 + 34 + 21 + 552 + 1 = 666.

It is not a de Polignac number, because 125534215521 - 2¹ = 125534215519 is a prime.

It is not an unprimeable number, because it can be changed into a prime (125534215721) 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 71 ways as a sum of consecutive naturals, for example, 7403365 + ... + 7420301.

It is an arithmetic number, because the mean of its divisors is an integer number (2981867148).

Almost surely, 2^125534215521 is an apocalyptic number.

125534215521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

125534215521 is a deficient number, since it is larger than the sum of its proper divisors (89160219135).

125534215521 is a wasteful number, since it uses less digits than its factorization.

125534215521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17423 (or 17407 counting only the distinct ones).

The product of its digits is 60000, while the sum is 36.

The spelling of 125534215521 in words is "one hundred twenty-five billion, five hundred thirty-four million, two hundred fifteen thousand, five hundred twenty-one".