21072625 has 16 divisors (see below), whose sum is σ = 30056832. Its totient is φ = 14449200.

The previous prime is 21072613. The next prime is 21072629. The reversal of 21072625 is 52627012.

It is not a de Polignac number, because 21072625 - 2⁵ = 21072593 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21072625.

It is not an unprimeable number, because it can be changed into a prime (21072629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11167 + ... + 12916.

It is an arithmetic number, because the mean of its divisors is an integer number (1878552).

Almost surely, 2^21072625 is an apocalyptic number.

21072625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21072625 is a deficient number, since it is larger than the sum of its proper divisors (8984207).

21072625 is an equidigital number, since it uses as much as digits as its factorization.

21072625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24105 (or 24095 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 21072625 is about 4590.4928929256. The cubic root of 21072625 is about 276.2100943565.

Adding to 21072625 its reverse (52627012), we get a palindrome (73699637).

The spelling of 21072625 in words is "twenty-one million, seventy-two thousand, six hundred twenty-five".