20072720 has 40 divisors (see below), whose sum is σ = 47246976. Its totient is φ = 7929728.

The previous prime is 20072711. The next prime is 20072729. The reversal of 20072720 is 2727002.

It is an interprime number because it is at equal distance from previous prime (20072711) and next prime (20072729).

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

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 20072692 and 20072701.

It is not an unprimeable number, because it can be changed into a prime (20072729) 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, 5129 + ... + 8151.

Almost surely, 2^20072720 is an apocalyptic number.

20072720 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 20072720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23623488).

20072720 is an abundant number, since it is smaller than the sum of its proper divisors (27174256).

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

20072720 is a wasteful number, since it uses less digits than its factorization.

20072720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3119 (or 3113 counting only the distinct ones).

The product of its (nonzero) digits is 392, while the sum is 20.

The square root of 20072720 is about 4480.2589210893. The cubic root of 20072720 is about 271.7703511454.

Adding to 20072720 its reverse (2727002), we get a palindrome (22799722).

The spelling of 20072720 in words is "twenty million, seventy-two thousand, seven hundred twenty".