125371381621 has 2 divisors, whose sum is σ = 125371381622. Its totient is φ = 125371381620.

The previous prime is 125371381613. The next prime is 125371381631. The reversal of 125371381621 is 126183173521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 125288389521 + 82992100 = 353961^2 + 9110^2 .

It is a cyclic number.

It is not a de Polignac number, because 125371381621 - 2³ = 125371381613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (125371381631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62685690810 + 62685690811.

It is an arithmetic number, because the mean of its divisors is an integer number (62685690811).

Almost surely, 2^125371381621 is an apocalyptic number.

It is an amenable number.

125371381621 is a deficient number, since it is larger than the sum of its proper divisors (1).

125371381621 is an equidigital number, since it uses as much as digits as its factorization.

125371381621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60480, while the sum is 40.

The spelling of 125371381621 in words is "one hundred twenty-five billion, three hundred seventy-one million, three hundred eighty-one thousand, six hundred twenty-one".