20811625 has 16 divisors (see below), whose sum is σ = 26103168. Its totient is φ = 16566000.

The previous prime is 20811611. The next prime is 20811653. The reversal of 20811625 is 52611802.

It is not a de Polignac number, because 20811625 - 2²¹ = 18714473 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 20811625.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41124 + ... + 41626.

It is an arithmetic number, because the mean of its divisors is an integer number (1631448).

Almost surely, 2^20811625 is an apocalyptic number.

20811625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20811625 is a deficient number, since it is larger than the sum of its proper divisors (5291543).

20811625 is an equidigital number, since it uses as much as digits as its factorization.

20811625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 849 (or 839 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 20811625 is about 4561.9759973064. The cubic root of 20811625 is about 275.0649984100.

The spelling of 20811625 in words is "twenty million, eight hundred eleven thousand, six hundred twenty-five".