20856860 has 24 divisors (see below), whose sum is σ = 45704736. Its totient is φ = 7979840.

The previous prime is 20856839. The next prime is 20856877. The reversal of 20856860 is 6865802.

It is a self number, because there is not a number n which added to its sum of digits gives 20856860.

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, 22211 + ... + 23130.

It is an arithmetic number, because the mean of its divisors is an integer number (1904364).

Almost surely, 2^20856860 is an apocalyptic number.

20856860 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20856860 is an abundant number, since it is smaller than the sum of its proper divisors (24847876).

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

20856860 is a wasteful number, since it uses less digits than its factorization.

20856860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45373 (or 45371 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 35.

The square root of 20856860 is about 4566.9311358942. The cubic root of 20856860 is about 275.2641428985.

The spelling of 20856860 in words is "twenty million, eight hundred fifty-six thousand, eight hundred sixty".