231120311220 has 72 divisors (see below), whose sum is σ = 701108704296. Its totient is φ = 61628236032.

The previous prime is 231120311183. The next prime is 231120311269. The reversal of 231120311220 is 22113021132.

231120311220 is a `hidden beast` number, since 2 + 311 + 20 + 311 + 2 + 20 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 63646207524 + 167474103696 = 252282^2 + 409236^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 231120311193 and 231120311202.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3954934 + ... + 4012946.

It is an arithmetic number, because the mean of its divisors is an integer number (9737620893).

Almost surely, 2^231120311220 is an apocalyptic number.

231120311220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

231120311220 is an abundant number, since it is smaller than the sum of its proper divisors (469988393076).

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

231120311220 is a wasteful number, since it uses less digits than its factorization.

231120311220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80161 (or 80156 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 231120311220 its reverse (22113021132), we get a palindrome (253233332352).

The spelling of 231120311220 in words is "two hundred thirty-one billion, one hundred twenty million, three hundred eleven thousand, two hundred twenty".