125729221 has 2 divisors, whose sum is σ = 125729222. Its totient is φ = 125729220.

The previous prime is 125729209. The next prime is 125729231. The reversal of 125729221 is 122927521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 123876900 + 1852321 = 11130^2 + 1361^2 .

It is a cyclic number.

It is not a de Polignac number, because 125729221 - 2⁵ = 125729189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (125729231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62864610 + 62864611.

It is an arithmetic number, because the mean of its divisors is an integer number (62864611).

Almost surely, 2^125729221 is an apocalyptic number.

It is an amenable number.

125729221 is a deficient number, since it is larger than the sum of its proper divisors (1).

125729221 is an equidigital number, since it uses as much as digits as its factorization.

125729221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5040, while the sum is 31.

The square root of 125729221 is about 11212.9042179089. The cubic root of 125729221 is about 500.9704100569.

The spelling of 125729221 in words is "one hundred twenty-five million, seven hundred twenty-nine thousand, two hundred twenty-one".