125357406521 has 2 divisors, whose sum is σ = 125357406522. Its totient is φ = 125357406520.

The previous prime is 125357406457. The next prime is 125357406523. The reversal of 125357406521 is 125604753521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 121357476496 + 3999930025 = 348364^2 + 63245^2 .

It is a cyclic number.

It is not a de Polignac number, because 125357406521 - 2⁶ = 125357406457 is a prime.

Together with 125357406523, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (125357406523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62678703260 + 62678703261.

It is an arithmetic number, because the mean of its divisors is an integer number (62678703261).

Almost surely, 2^125357406521 is an apocalyptic number.

It is an amenable number.

125357406521 is a deficient number, since it is larger than the sum of its proper divisors (1).

125357406521 is an equidigital number, since it uses as much as digits as its factorization.

125357406521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 252000, while the sum is 41.

The spelling of 125357406521 in words is "one hundred twenty-five billion, three hundred fifty-seven million, four hundred six thousand, five hundred twenty-one".