20801920 has 32 divisors (see below), whose sum is σ = 49731120. Its totient is φ = 8320512.

The previous prime is 20801909. The next prime is 20801923. The reversal of 20801920 is 2910802.

It is a tau number, because it is divible by the number of its divisors (32).

It is a junction number, because it is equal to n+sod(n) for n = 20801891 and 20801900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20801923) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 15612 + ... + 16891.

Almost surely, 2^20801920 is an apocalyptic number.

20801920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20801920 is an abundant number, since it is smaller than the sum of its proper divisors (28929200).

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

20801920 is an equidigital number, since it uses as much as digits as its factorization.

20801920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32522 (or 32510 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 20801920 is about 4560.9121894639. The cubic root of 20801920 is about 275.0222351167.

The spelling of 20801920 in words is "twenty million, eight hundred one thousand, nine hundred twenty".