22781664 has 36 divisors (see below), whose sum is σ = 64786176. Its totient is φ = 7593792.

The previous prime is 22781663. The next prime is 22781669. The reversal of 22781664 is 46618722.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22781663) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 39264 + ... + 39839.

It is an arithmetic number, because the mean of its divisors is an integer number (1799616).

Almost surely, 2^22781664 is an apocalyptic number.

22781664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

22781664 is an abundant number, since it is smaller than the sum of its proper divisors (42004512).

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

22781664 is a wasteful number, since it uses less digits than its factorization.

22781664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79119 (or 79108 counting only the distinct ones).

The product of its digits is 32256, while the sum is 36.

The square root of 22781664 is about 4773.0141420281. The cubic root of 22781664 is about 283.4839534417.

The spelling of 22781664 in words is "twenty-two million, seven hundred eighty-one thousand, six hundred sixty-four".