20804425 has 12 divisors (see below), whose sum is σ = 26427996. Its totient is φ = 16236800.

The previous prime is 20804401. The next prime is 20804431. The reversal of 20804425 is 52440802.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 3697929 + 17106496 = 1923^2 + 4136^2 .

It is not a de Polignac number, because 20804425 - 2¹³ = 20796233 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 20804425.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9124 + ... + 11173.

It is an arithmetic number, because the mean of its divisors is an integer number (2202333).

Almost surely, 2^20804425 is an apocalyptic number.

20804425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20804425 is a deficient number, since it is larger than the sum of its proper divisors (5623571).

20804425 is a wasteful number, since it uses less digits than its factorization.

20804425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20348 (or 20343 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 25.

The square root of 20804425 is about 4561.1867973149. The cubic root of 20804425 is about 275.0332742107.

The spelling of 20804425 in words is "twenty million, eight hundred four thousand, four hundred twenty-five".