20808500 has 24 divisors (see below), whose sum is σ = 45446856. Its totient is φ = 8323200.

The previous prime is 20808499. The next prime is 20808509. The reversal of 20808500 is 580802.

It can be written as a sum of positive squares in 4 ways, for example, as 630436 + 20178064 = 794^2 + 4492^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20808509) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20309 + ... + 21308.

It is an arithmetic number, because the mean of its divisors is an integer number (1893619).

Almost surely, 2^20808500 is an apocalyptic number.

20808500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20808500 is an abundant number, since it is smaller than the sum of its proper divisors (24638356).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20808500 is a wasteful number, since it uses less digits than its factorization.

20808500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41636 (or 41624 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 23.

The square root of 20808500 is about 4561.6334793580. The cubic root of 20808500 is about 275.0512301251.

The spelling of 20808500 in words is "twenty million, eight hundred eight thousand, five hundred".