21358125 has 30 divisors (see below), whose sum is σ = 38561094. Its totient is φ = 11388000.

The previous prime is 21358111. The next prime is 21358133. The reversal of 21358125 is 52185312.

It is a happy number.

It can be written as a sum of positive squares in 5 ways, for example, as 15350724 + 6007401 = 3918^2 + 2451^2 .

It is not a de Polignac number, because 21358125 - 2⁷ = 21357997 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 3727 + ... + 7523.

Almost surely, 2^21358125 is an apocalyptic number.

21358125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21358125 is a deficient number, since it is larger than the sum of its proper divisors (17202969).

21358125 is an equidigital number, since it uses as much as digits as its factorization.

21358125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3823 (or 3805 counting only the distinct ones).

The product of its digits is 2400, while the sum is 27.

The square root of 21358125 is about 4621.4851509012. The cubic root of 21358125 is about 277.4519030350.

The spelling of 21358125 in words is "twenty-one million, three hundred fifty-eight thousand, one hundred twenty-five".