20312131220 has 24 divisors (see below), whose sum is σ = 44510062464. Its totient is φ = 7771597856.

The previous prime is 20312131219. The next prime is 20312131261. The reversal of 20312131220 is 2213121302.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22077944 + ... + 22078863.

It is an arithmetic number, because the mean of its divisors is an integer number (1854585936).

Almost surely, 2^20312131220 is an apocalyptic number.

20312131220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20312131220 is an abundant number, since it is smaller than the sum of its proper divisors (24197931244).

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

20312131220 is a wasteful number, since it uses less digits than its factorization.

20312131220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44156839 (or 44156837 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 20312131220 its reverse (2213121302), we get a palindrome (22525252522).

The spelling of 20312131220 in words is "twenty billion, three hundred twelve million, one hundred thirty-one thousand, two hundred twenty".