20764836 has 42 divisors (see below), whose sum is σ = 54490422. Its totient is φ = 6920640.

The previous prime is 20764813. The next prime is 20764847. The reversal of 20764836 is 63846702.

20764836 is a `hidden beast` number, since 2 + 0 + 7 + 648 + 3 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 11943936 + 8820900 = 3456^2 + 2970^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 20764836.

It is an unprimeable number.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 645 + ... + 6476.

It is an arithmetic number, because the mean of its divisors is an integer number (1297391).

Almost surely, 2^20764836 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20764836, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27245211).

20764836 is an abundant number, since it is smaller than the sum of its proper divisors (33725586).

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

20764836 is an equidigital number, since it uses as much as digits as its factorization.

20764836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7143 (or 7126 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 36.

The square root of 20764836 is about 4556.8449611546. The cubic root of 20764836 is about 274.8587086861.

The spelling of 20764836 in words is "twenty million, seven hundred sixty-four thousand, eight hundred thirty-six".