20956900 has 18 divisors (see below), whose sum is σ = 45476690. Its totient is φ = 8382720.

The previous prime is 20956861. The next prime is 20956907. The reversal of 20956900 is 965902.

It can be written as a sum of positive squares in 3 ways, for example, as 236196 + 20720704 = 486^2 + 4552^2 .

It is a super-2 number, since 2×20956900² = 878383315220000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20956907) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 104685 + ... + 104884.

Almost surely, 2^20956900 is an apocalyptic number.

20956900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20956900 is an abundant number, since it is smaller than the sum of its proper divisors (24519790).

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

20956900 is a wasteful number, since it uses less digits than its factorization.

20956900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209583 (or 209576 counting only the distinct ones).

The product of its (nonzero) digits is 4860, while the sum is 31.

The square root of 20956900 is about 4577.8706840626. The cubic root of 20956900 is about 275.7035429172.

The spelling of 20956900 in words is "twenty million, nine hundred fifty-six thousand, nine hundred".