125616521 has 2 divisors, whose sum is σ = 125616522. Its totient is φ = 125616520.

The previous prime is 125616509. The next prime is 125616539.

It is a happy number.

125616521 is nontrivially palindromic in base 10.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 118026496 + 7590025 = 10864^2 + 2755^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 125616521 - 2¹⁸ = 125354377 is a prime.

It is a Chen prime.

It is an alternating number because its digits alternate between odd and even.

It is not a weakly prime, because it can be changed into another prime (125616551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62808260 + 62808261.

It is an arithmetic number, because the mean of its divisors is an integer number (62808261).

Almost surely, 2^125616521 is an apocalyptic number.

It is an amenable number.

125616521 is a deficient number, since it is larger than the sum of its proper divisors (1).

125616521 is an equidigital number, since it uses as much as digits as its factorization.

125616521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3600, while the sum is 29.

The square root of 125616521 is about 11207.8776313805. The cubic root of 125616521 is about 500.8206802309.

The spelling of 125616521 in words is "one hundred twenty-five million, six hundred sixteen thousand, five hundred twenty-one".