20711880 has 96 divisors (see below), whose sum is σ = 76939200. Its totient is φ = 4733568.

The previous prime is 20711869. The next prime is 20711893. The reversal of 20711880 is 8811702.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1590 + ... + 6629.

It is an arithmetic number, because the mean of its divisors is an integer number (801450).

Almost surely, 2^20711880 is an apocalyptic number.

20711880 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 20711880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38469600).

20711880 is an abundant number, since it is smaller than the sum of its proper divisors (56227320).

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

20711880 is a wasteful number, since it uses less digits than its factorization.

20711880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8243 (or 8236 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 27.

The square root of 20711880 is about 4551.0306525006. The cubic root of 20711880 is about 274.6248548644.

The spelling of 20711880 in words is "twenty million, seven hundred eleven thousand, eight hundred eighty".