125402021 has 2 divisors, whose sum is σ = 125402022. Its totient is φ = 125402020.

The previous prime is 125402009. The next prime is 125402029. The reversal of 125402021 is 120204521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 124322500 + 1079521 = 11150^2 + 1039^2 .

It is a cyclic number.

It is not a de Polignac number, because 125402021 - 2¹⁸ = 125139877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (125402029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62701010 + 62701011.

It is an arithmetic number, because the mean of its divisors is an integer number (62701011).

Almost surely, 2^125402021 is an apocalyptic number.

It is an amenable number.

125402021 is a deficient number, since it is larger than the sum of its proper divisors (1).

125402021 is an equidigital number, since it uses as much as digits as its factorization.

125402021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 125402021 is about 11198.3043805748. The cubic root of 125402021 is about 500.5354543725.

Adding to 125402021 its reverse (120204521), we get a palindrome (245606542).

The spelling of 125402021 in words is "one hundred twenty-five million, four hundred two thousand, twenty-one".