125206721 has 2 divisors, whose sum is σ = 125206722. Its totient is φ = 125206720.

The previous prime is 125206693. The next prime is 125206759. The reversal of 125206721 is 127602521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 104857600 + 20349121 = 10240^2 + 4511^2 .

It is a cyclic number.

It is not a de Polignac number, because 125206721 - 2²² = 121012417 is a prime.

It is equal to p_7121186 and since 125206721 and 7121186 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 (125206321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62603360 + 62603361.

It is an arithmetic number, because the mean of its divisors is an integer number (62603361).

Almost surely, 2^125206721 is an apocalyptic number.

It is an amenable number.

125206721 is a deficient number, since it is larger than the sum of its proper divisors (1).

125206721 is an equidigital number, since it uses as much as digits as its factorization.

125206721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 125206721 is about 11189.5809126169. The cubic root of 125206721 is about 500.2754761979.

The spelling of 125206721 in words is "one hundred twenty-five million, two hundred six thousand, seven hundred twenty-one".