20808725 has 12 divisors (see below), whose sum is σ = 29489184. Its totient is φ = 14268720.

The previous prime is 20808713. The next prime is 20808737. The reversal of 20808725 is 52780802.

It is an interprime number because it is at equal distance from previous prime (20808713) and next prime (20808737).

It is not a de Polignac number, because 20808725 - 2¹⁴ = 20792341 is a prime.

It is a super-2 number, since 2×20808725² = 866006072251250, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20808691 and 20808700.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 59279 + ... + 59628.

It is an arithmetic number, because the mean of its divisors is an integer number (2457432).

Almost surely, 2^20808725 is an apocalyptic number.

20808725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20808725 is a deficient number, since it is larger than the sum of its proper divisors (8680459).

20808725 is a wasteful number, since it uses less digits than its factorization.

20808725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118924 (or 118919 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 32.

The square root of 20808725 is about 4561.6581415095. The cubic root of 20808725 is about 275.0522214877.

The spelling of 20808725 in words is "twenty million, eight hundred eight thousand, seven hundred twenty-five".