125122721 has 4 divisors (see below), whose sum is σ = 125247252. Its totient is φ = 124998192.

The previous prime is 125122717. The next prime is 125122729. The reversal of 125122721 is 127221521.

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 130321 + 124992400 = 361^2 + 11180^2 .

It is a cyclic number.

It is not a de Polignac number, because 125122721 - 2² = 125122717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (125122729) 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, 60746 + ... + 62771.

It is an arithmetic number, because the mean of its divisors is an integer number (31311813).

Almost surely, 2^125122721 is an apocalyptic number.

It is an amenable number.

125122721 is a deficient number, since it is larger than the sum of its proper divisors (124531).

125122721 is a wasteful number, since it uses less digits than its factorization.

125122721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124530.

The product of its digits is 560, while the sum is 23.

The square root of 125122721 is about 11185.8267910781. The cubic root of 125122721 is about 500.1635744809.

The spelling of 125122721 in words is "one hundred twenty-five million, one hundred twenty-two thousand, seven hundred twenty-one".