20753664 has 72 divisors (see below), whose sum is σ = 56267232. Its totient is φ = 6789120.

The previous prime is 20753639. The next prime is 20753683. The reversal of 20753664 is 46635702.

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, 46627 + ... + 47069.

Almost surely, 2^20753664 is an apocalyptic number.

20753664 is a gapful number since it is divisible by the number (24) 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 20753664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28133616).

20753664 is an abundant number, since it is smaller than the sum of its proper divisors (35513568).

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

20753664 is an equidigital number, since it uses as much as digits as its factorization.

20753664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 523 (or 509 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 33.

The square root of 20753664 is about 4555.6189480684. The cubic root of 20753664 is about 274.8094062280.

The spelling of 20753664 in words is "twenty million, seven hundred fifty-three thousand, six hundred sixty-four".