125221101521 has 4 divisors (see below), whose sum is σ = 125621169252. Its totient is φ = 124821033792.

The previous prime is 125221101517. The next prime is 125221101559. The reversal of 125221101521 is 125101122521.

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 40455690496 + 84765411025 = 201136^2 + 291145^2 .

It is a cyclic number.

It is not a de Polignac number, because 125221101521 - 2² = 125221101517 is a prime.

It is a super-2 number, since 2×125221101521² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (125221107521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 200033396 + ... + 200034021.

It is an arithmetic number, because the mean of its divisors is an integer number (31405292313).

Almost surely, 2^125221101521 is an apocalyptic number.

It is an amenable number.

125221101521 is a deficient number, since it is larger than the sum of its proper divisors (400067731).

125221101521 is an equidigital number, since it uses as much as digits as its factorization.

125221101521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 400067730.

The product of its (nonzero) digits is 400, while the sum is 23.

The spelling of 125221101521 in words is "one hundred twenty-five billion, two hundred twenty-one million, one hundred one thousand, five hundred twenty-one".