20209820 has 12 divisors (see below), whose sum is σ = 42440664. Its totient is φ = 8083920.

The previous prime is 20209811. The next prime is 20209837. The reversal of 20209820 is 2890202.

It is a hoax number, since the sum of its digits (23) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 505226 + ... + 505265.

It is an arithmetic number, because the mean of its divisors is an integer number (3536722).

Almost surely, 2^20209820 is an apocalyptic number.

20209820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20209820 is an abundant number, since it is smaller than the sum of its proper divisors (22230844).

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

20209820 is a wasteful number, since it uses less digits than its factorization.

20209820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1010500 (or 1010498 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 20209820 is about 4495.5333387708. The cubic root of 20209820 is about 272.3876932489.

The spelling of 20209820 in words is "twenty million, two hundred nine thousand, eight hundred twenty".