20722440 has 32 divisors (see below), whose sum is σ = 62167680. Its totient is φ = 5525952.

The previous prime is 20722433. The next prime is 20722447. The reversal of 20722440 is 4422702.

It is an interprime number because it is at equal distance from previous prime (20722433) and next prime (20722447).

It is not an unprimeable number, because it can be changed into a prime (20722447) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 86224 + ... + 86463.

It is an arithmetic number, because the mean of its divisors is an integer number (1942740).

Almost surely, 2^20722440 is an apocalyptic number.

20722440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20722440 is an abundant number, since it is smaller than the sum of its proper divisors (41445240).

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

20722440 is a wasteful number, since it uses less digits than its factorization.

20722440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172701 (or 172697 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 21.

The square root of 20722440 is about 4552.1906814192. The cubic root of 20722440 is about 274.6715196407.

The spelling of 20722440 in words is "twenty million, seven hundred twenty-two thousand, four hundred forty".