20331264 has 72 divisors (see below), whose sum is σ = 56512512. Its totient is φ = 6476800.

The previous prime is 20331263. The next prime is 20331271. The reversal of 20331264 is 46213302.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 20331264.

It is not an unprimeable number, because it can be changed into a prime (20331263) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17089 + ... + 18239.

It is an arithmetic number, because the mean of its divisors is an integer number (784896).

Almost surely, 2^20331264 is an apocalyptic number.

20331264 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 20331264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28256256).

20331264 is an abundant number, since it is smaller than the sum of its proper divisors (36181248).

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

20331264 is a wasteful number, since it uses less digits than its factorization.

20331264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1193 (or 1179 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 21.

The square root of 20331264 is about 4509.0202927022. The cubic root of 20331264 is about 272.9322108920.

Adding to 20331264 its reverse (46213302), we get a palindrome (66544566).

The spelling of 20331264 in words is "twenty million, three hundred thirty-one thousand, two hundred sixty-four".