20906920 has 16 divisors (see below), whose sum is σ = 47040660. Its totient is φ = 8362752.

The previous prime is 20906917. The next prime is 20906929. The reversal of 20906920 is 2960902.

It can be written as a sum of positive squares in 2 ways, for example, as 20848356 + 58564 = 4566^2 + 242^2 .

It is not an unprimeable number, because it can be changed into a prime (20906929) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 261297 + ... + 261376.

Almost surely, 2^20906920 is an apocalyptic number.

20906920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20906920 is an abundant number, since it is smaller than the sum of its proper divisors (26133740).

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

20906920 is a wasteful number, since it uses less digits than its factorization.

20906920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 522684 (or 522680 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 20906920 is about 4572.4085556739. The cubic root of 20906920 is about 275.4841938093.

The spelling of 20906920 in words is "twenty million, nine hundred six thousand, nine hundred twenty".