22931640 has 128 divisors (see below), whose sum is σ = 81000000. Its totient is φ = 5750784.

The previous prime is 22931639. The next prime is 22931641. The reversal of 22931640 is 4613922.

It is an interprime number because it is at equal distance from previous prime (22931639) and next prime (22931641).

It is a super-2 number, since 2×22931640² = 1051720226179200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22931641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17736 + ... + 18984.

Almost surely, 2^22931640 is an apocalyptic number.

22931640 is a gapful number since it is divisible by the number (20) 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 22931640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40500000).

22931640 is an abundant number, since it is smaller than the sum of its proper divisors (58068360).

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

22931640 is a wasteful number, since it uses less digits than its factorization.

22931640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1286 (or 1276 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 22931640 is about 4788.6991970680. The cubic root of 22931640 is about 284.1046694794.

The spelling of 22931640 in words is "twenty-two million, nine hundred thirty-one thousand, six hundred forty".