22688640 has 256 divisors, whose sum is σ = 87393600. Its totient is φ = 5529600.

The previous prime is 22688599. The next prime is 22688647. The reversal of 22688640 is 4688622.

22688640 is a `hidden beast` number, since 2 + 2 + 6 + 8 + 8 + 640 = 666.

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

It is a nialpdrome in base 12.

It is a zygodrome in base 12.

It is a junction number, because it is equal to n+sod(n) for n = 22688595 and 22688604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22688647) 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, 224590 + ... + 224690.

Almost surely, 2^22688640 is an apocalyptic number.

22688640 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 22688640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43696800).

22688640 is an abundant number, since it is smaller than the sum of its proper divisors (64704960).

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

22688640 is a wasteful number, since it uses less digits than its factorization.

22688640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142 (or 124 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 36.

The square root of 22688640 is about 4763.2593882761. The cubic root of 22688640 is about 283.0975785907.

The spelling of 22688640 in words is "twenty-two million, six hundred eighty-eight thousand, six hundred forty".