125425021 has 4 divisors (see below), whose sum is σ = 125699932. Its totient is φ = 125150112.

The previous prime is 125425009. The next prime is 125425037. The reversal of 125425021 is 120524521.

125425021 = 279² + 280² + ... + 735².

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 75933796 + 49491225 = 8714^2 + 7035^2 .

It is a cyclic number.

It is not a de Polignac number, because 125425021 - 2⁵ = 125424989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 125424983 and 125425001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125425051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 136770 + ... + 137683.

It is an arithmetic number, because the mean of its divisors is an integer number (31424983).

Almost surely, 2^125425021 is an apocalyptic number.

It is an amenable number.

125425021 is a deficient number, since it is larger than the sum of its proper divisors (274911).

125425021 is an equidigital number, since it uses as much as digits as its factorization.

125425021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274910.

The product of its (nonzero) digits is 800, while the sum is 22.

The square root of 125425021 is about 11199.3312746789. The cubic root of 125425021 is about 500.5660535915.

Adding to 125425021 its reverse (120524521), we get a palindrome (245949542).

The spelling of 125425021 in words is "one hundred twenty-five million, four hundred twenty-five thousand, twenty-one".