231220204220 has 24 divisors (see below), whose sum is σ = 485635867584. Its totient is φ = 92474093376.

The previous prime is 231220204213. The next prime is 231220204309. The reversal of 231220204220 is 22402022132.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 231220204192 and 231220204201.

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, 738212 + ... + 1003691.

It is an arithmetic number, because the mean of its divisors is an integer number (20234827816).

Almost surely, 2^231220204220 is an apocalyptic number.

231220204220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

231220204220 is an abundant number, since it is smaller than the sum of its proper divisors (254415663364).

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

231220204220 is a wasteful number, since it uses less digits than its factorization.

231220204220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1748549 (or 1748547 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

Adding to 231220204220 its reverse (22402022132), we get a palindrome (253622226352).

The spelling of 231220204220 in words is "two hundred thirty-one billion, two hundred twenty million, two hundred four thousand, two hundred twenty".