231122220 has 144 divisors (see below), whose sum is σ = 759951360. Its totient is φ = 52327296.

The previous prime is 231122189. The next prime is 231122273. The reversal of 231122220 is 22221132.

It is a happy number.

231122220 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 231122220.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 373071 + ... + 373689.

It is an arithmetic number, because the mean of its divisors is an integer number (5277440).

Almost surely, 2^231122220 is an apocalyptic number.

231122220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 231122220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (379975680).

231122220 is an abundant number, since it is smaller than the sum of its proper divisors (528829140).

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

231122220 is a wasteful number, since it uses less digits than its factorization.

231122220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 772 (or 763 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 231122220 is about 15202.7043646846. The cubic root of 231122220 is about 613.6874379536.

Adding to 231122220 its reverse (22221132), we get a palindrome (253343352).

It can be divided in two parts, 2311 and 22220, that added together give a triangular number (24531 = T₂₂₁).

The spelling of 231122220 in words is "two hundred thirty-one million, one hundred twenty-two thousand, two hundred twenty".