20220720 has 80 divisors (see below), whose sum is σ = 67516512. Its totient is φ = 4976640.

The previous prime is 20220713. The next prime is 20220751. The reversal of 20220720 is 2702202.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 20220720.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 121 + ... + 6360.

Almost surely, 2^20220720 is an apocalyptic number.

20220720 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 20220720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33758256).

20220720 is an abundant number, since it is smaller than the sum of its proper divisors (47295792).

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

20220720 is a wasteful number, since it uses less digits than its factorization.

20220720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6510 (or 6504 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 15.

The square root of 20220720 is about 4496.7454897959. The cubic root of 20220720 is about 272.4366544675.

Adding to 20220720 its reverse (2702202), we get a palindrome (22922922).

The spelling of 20220720 in words is "twenty million, two hundred twenty thousand, seven hundred twenty".