125121961 has 2 divisors, whose sum is σ = 125121962. Its totient is φ = 125121960.

The previous prime is 125121929. The next prime is 125121977. The reversal of 125121961 is 169121521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 76387600 + 48734361 = 8740^2 + 6981^2 .

It is an emirp because it is prime and its reverse (169121521) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 125121961 - 2⁵ = 125121929 is a prime.

It is equal to p_7116652 and since 125121961 and 7116652 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (125121761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62560980 + 62560981.

It is an arithmetic number, because the mean of its divisors is an integer number (62560981).

Almost surely, 2^125121961 is an apocalyptic number.

It is an amenable number.

125121961 is a deficient number, since it is larger than the sum of its proper divisors (1).

125121961 is an equidigital number, since it uses as much as digits as its factorization.

125121961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1080, while the sum is 28.

The square root of 125121961 is about 11185.7928194652. The cubic root of 125121961 is about 500.1625618083.

The spelling of 125121961 in words is "one hundred twenty-five million, one hundred twenty-one thousand, nine hundred sixty-one".