20810920 has 64 divisors (see below), whose sum is σ = 52093440. Its totient is φ = 7430400.

The previous prime is 20810897. The next prime is 20810981. The reversal of 20810920 is 2901802.

It is a junction number, because it is equal to n+sod(n) for n = 20810891 and 20810900.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15475 + ... + 16765.

It is an arithmetic number, because the mean of its divisors is an integer number (813960).

Almost surely, 2^20810920 is an apocalyptic number.

20810920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20810920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26046720).

20810920 is an abundant number, since it is smaller than the sum of its proper divisors (31282520).

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

20810920 is a wasteful number, since it uses less digits than its factorization.

20810920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1346 (or 1342 counting only the distinct ones).

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

The square root of 20810920 is about 4561.8987275037. The cubic root of 20810920 is about 275.0618924053.

The spelling of 20810920 in words is "twenty million, eight hundred ten thousand, nine hundred twenty".