20207221220 has 12 divisors (see below), whose sum is σ = 42435164604. Its totient is φ = 8082888480.

The previous prime is 20207221217. The next prime is 20207221253. The reversal of 20207221220 is 2212270202.

It can be written as a sum of positive squares in 2 ways, for example, as 4359432676 + 15847788544 = 66026^2 + 125888^2 .

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 1010361061 = 20207221220 / (2 + 0 + 2 + 0 + 7 + 2 + 2 + 1 + 2 + 2 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 20207221192 and 20207221201.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 505180511 + ... + 505180550.

It is an arithmetic number, because the mean of its divisors is an integer number (3536263717).

Almost surely, 2^20207221220 is an apocalyptic number.

20207221220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20207221220 is an abundant number, since it is smaller than the sum of its proper divisors (22227943384).

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

20207221220 is a wasteful number, since it uses less digits than its factorization.

20207221220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1010361070 (or 1010361068 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 20.

Adding to 20207221220 its reverse (2212270202), we get a palindrome (22419491422).

The spelling of 20207221220 in words is "twenty billion, two hundred seven million, two hundred twenty-one thousand, two hundred twenty".