20313220 has 12 divisors (see below), whose sum is σ = 42657804. Its totient is φ = 8125280.

The previous prime is 20313203. The next prime is 20313229. The reversal of 20313220 is 2231302.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 4056196 + 16257024 = 2014^2 + 4032^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20313220.

It is not an unprimeable number, because it can be changed into a prime (20313229) 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, 507811 + ... + 507850.

It is an arithmetic number, because the mean of its divisors is an integer number (3554817).

Almost surely, 2^20313220 is an apocalyptic number.

20313220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20313220 is an abundant number, since it is smaller than the sum of its proper divisors (22344584).

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

20313220 is a wasteful number, since it uses less digits than its factorization.

20313220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1015670 (or 1015668 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 13.

The square root of 20313220 is about 4507.0189704504. The cubic root of 20313220 is about 272.8514445339.

Adding to 20313220 its reverse (2231302), we get a palindrome (22544522).

The spelling of 20313220 in words is "twenty million, three hundred thirteen thousand, two hundred twenty".