20972020 has 12 divisors (see below), whose sum is σ = 44041284. Its totient is φ = 8388800.

The previous prime is 20971997. The next prime is 20972023. The reversal of 20972020 is 2027902.

It can be written as a sum of positive squares in 2 ways, for example, as 16695396 + 4276624 = 4086^2 + 2068^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20971982 and 20972000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20972023) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 524281 + ... + 524320.

It is an arithmetic number, because the mean of its divisors is an integer number (3670107).

Almost surely, 2^20972020 is an apocalyptic number.

20972020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20972020 is an abundant number, since it is smaller than the sum of its proper divisors (23069264).

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

20972020 is a wasteful number, since it uses less digits than its factorization.

20972020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1048610 (or 1048608 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 22.

The square root of 20972020 is about 4579.5218090975. The cubic root of 20972020 is about 275.7698319110.

Adding to 20972020 its reverse (2027902), we get a palindrome (22999922).

The spelling of 20972020 in words is "twenty million, nine hundred seventy-two thousand, twenty".