22721440 has 48 divisors (see below), whose sum is σ = 61350912. Its totient is φ = 7789824.

The previous prime is 22721437. The next prime is 22721467. The reversal of 22721440 is 4412722.

It is a happy number.

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, 9024 + ... + 11263.

It is an arithmetic number, because the mean of its divisors is an integer number (1278144).

Almost surely, 2^22721440 is an apocalyptic number.

22721440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

22721440 is an abundant number, since it is smaller than the sum of its proper divisors (38629472).

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

22721440 is a wasteful number, since it uses less digits than its factorization.

22721440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20309 (or 20301 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 22.

The square root of 22721440 is about 4766.7011653763. The cubic root of 22721440 is about 283.2339336061.

The spelling of 22721440 in words is "twenty-two million, seven hundred twenty-one thousand, four hundred forty".