20888720 has 40 divisors (see below), whose sum is σ = 49885944. Its totient is φ = 8128512.

The previous prime is 20888717. The next prime is 20888723. The reversal of 20888720 is 2788802.

It is an interprime number because it is at equal distance from previous prime (20888717) and next prime (20888723).

It can be written as a sum of positive squares in 4 ways, for example, as 13424896 + 7463824 = 3664^2 + 2732^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (20888723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 569 + ... + 6488.

Almost surely, 2^20888720 is an apocalyptic number.

20888720 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 20888720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24942972).

20888720 is an abundant number, since it is smaller than the sum of its proper divisors (28997224).

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

20888720 is a wasteful number, since it uses less digits than its factorization.

20888720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7107 (or 7101 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 35.

The square root of 20888720 is about 4570.4179239978. The cubic root of 20888720 is about 275.4042319607.

The spelling of 20888720 in words is "twenty million, eight hundred eighty-eight thousand, seven hundred twenty".