22720640 has 64 divisors (see below), whose sum is σ = 54933120. Its totient is φ = 8985600.

The previous prime is 22720631. The next prime is 22720673. The reversal of 22720640 is 4602722.

It is a tau number, because it is divible by the number of its divisors (64).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 83705 + ... + 83975.

It is an arithmetic number, because the mean of its divisors is an integer number (858330).

Almost surely, 2^22720640 is an apocalyptic number.

22720640 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 22720640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27466560).

22720640 is an abundant number, since it is smaller than the sum of its proper divisors (32212480).

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

22720640 is a wasteful number, since it uses less digits than its factorization.

22720640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 421 (or 409 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 23.

The square root of 22720640 is about 4766.6172491611. The cubic root of 22720640 is about 283.2306094358.

The spelling of 22720640 in words is "twenty-two million, seven hundred twenty thousand, six hundred forty".