20808820 has 24 divisors (see below), whose sum is σ = 43914528. Its totient is φ = 8282400.

The previous prime is 20808803. The next prime is 20808829. The reversal of 20808820 is 2880802.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20808829) 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, 1755 + ... + 6685.

It is an arithmetic number, because the mean of its divisors is an integer number (1829772).

Almost surely, 2^20808820 is an apocalyptic number.

20808820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20808820 is an abundant number, since it is smaller than the sum of its proper divisors (23105708).

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

20808820 is a wasteful number, since it uses less digits than its factorization.

20808820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5151 (or 5149 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 28.

The square root of 20808820 is about 4561.6685543779. The cubic root of 20808820 is about 275.0526400608.

The spelling of 20808820 in words is "twenty million, eight hundred eight thousand, eight hundred twenty".