20812860 has 72 divisors (see below), whose sum is σ = 64624560. Its totient is φ = 5419008.

The previous prime is 20812849. The next prime is 20812877. The reversal of 20812860 is 6821802.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6396 + ... + 9084.

Almost surely, 2^20812860 is an apocalyptic number.

20812860 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 20812860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32312280).

20812860 is an abundant number, since it is smaller than the sum of its proper divisors (43811700).

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

20812860 is a wasteful number, since it uses less digits than its factorization.

20812860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2747 (or 2742 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 20812860 is about 4562.1113533100. Note that the first 3 decimals coincide. The cubic root of 20812860 is about 275.0704392562.

The spelling of 20812860 in words is "twenty million, eight hundred twelve thousand, eight hundred sixty".