20951560 has 32 divisors (see below), whose sum is σ = 53876160. Its totient is φ = 7183296.

The previous prime is 20951537. The next prime is 20951573. The reversal of 20951560 is 6515902.

It is a Harshad number since it is a multiple of its sum of digits (28).

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, 37134 + ... + 37693.

It is an arithmetic number, because the mean of its divisors is an integer number (1683630).

Almost surely, 2^20951560 is an apocalyptic number.

20951560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20951560 is an abundant number, since it is smaller than the sum of its proper divisors (32924600).

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

20951560 is a wasteful number, since it uses less digits than its factorization.

20951560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74845 (or 74841 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 28.

The square root of 20951560 is about 4577.2874063139. The cubic root of 20951560 is about 275.6801237095.

It can be divided in two parts, 2095 and 1560, that added together give a triangular number (3655 = T₈₅).

The spelling of 20951560 in words is "twenty million, nine hundred fifty-one thousand, five hundred sixty".