20663456 has 48 divisors (see below), whose sum is σ = 45360000. Its totient is φ = 9185280.

The previous prime is 20663437. The next prime is 20663471. The reversal of 20663456 is 65436602.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15920 + ... + 17168.

It is an arithmetic number, because the mean of its divisors is an integer number (945000).

Almost surely, 2^20663456 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 20663456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22680000).

20663456 is an abundant number, since it is smaller than the sum of its proper divisors (24696544).

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

20663456 is a wasteful number, since it uses less digits than its factorization.

20663456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1317 (or 1309 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 32.

The square root of 20663456 is about 4545.7074256929. The cubic root of 20663456 is about 274.4106652095.

The spelling of 20663456 in words is "twenty million, six hundred sixty-three thousand, four hundred fifty-six".