20956220 has 24 divisors (see below), whose sum is σ = 45922464. Its totient is φ = 8017856.

The previous prime is 20956211. The next prime is 20956261. The reversal of 20956220 is 2265902.

It is a self number, because there is not a number n which added to its sum of digits gives 20956220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22319 + ... + 23238.

It is an arithmetic number, because the mean of its divisors is an integer number (1913436).

Almost surely, 2^20956220 is an apocalyptic number.

20956220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20956220 is an abundant number, since it is smaller than the sum of its proper divisors (24966244).

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

20956220 is a wasteful number, since it uses less digits than its factorization.

20956220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45589 (or 45587 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 20956220 is about 4577.7964131228. The cubic root of 20956220 is about 275.7005609171.

The spelling of 20956220 in words is "twenty million, nine hundred fifty-six thousand, two hundred twenty".