125215621081 has 2 divisors, whose sum is σ = 125215621082. Its totient is φ = 125215621080.

The previous prime is 125215621079. The next prime is 125215621159. The reversal of 125215621081 is 180126512521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 121284331081 + 3931290000 = 348259^2 + 62700^2 .

It is a cyclic number.

It is not a de Polignac number, because 125215621081 - 2¹ = 125215621079 is a prime.

It is a super-2 number, since 2×125215621081² (a number of 23 digits) contains 22 as substring.

Together with 125215621079, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (125215621061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62607810540 + 62607810541.

It is an arithmetic number, because the mean of its divisors is an integer number (62607810541).

Almost surely, 2^125215621081 is an apocalyptic number.

It is an amenable number.

125215621081 is a deficient number, since it is larger than the sum of its proper divisors (1).

125215621081 is an equidigital number, since it uses as much as digits as its factorization.

125215621081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9600, while the sum is 34.

The spelling of 125215621081 in words is "one hundred twenty-five billion, two hundred fifteen million, six hundred twenty-one thousand, eighty-one".