231011220 has 96 divisors (see below), whose sum is σ = 722929536. Its totient is φ = 54630400.

The previous prime is 231011219. The next prime is 231011227. The reversal of 231011220 is 22110132.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 231011196 and 231011205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231011227) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 22792 + ... + 31328.

It is an arithmetic number, because the mean of its divisors is an integer number (7530516).

Almost surely, 2^231011220 is an apocalyptic number.

231011220 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 231011220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (361464768).

231011220 is an abundant number, since it is smaller than the sum of its proper divisors (491918316).

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

231011220 is a wasteful number, since it uses less digits than its factorization.

231011220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8601 (or 8599 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 231011220 is about 15199.0532599896. The cubic root of 231011220 is about 613.5891779455.

Adding to 231011220 its reverse (22110132), we get a palindrome (253121352).

It can be divided in two parts, 2310112 and 20, that added together give a palindrome (2310132).

The spelling of 231011220 in words is "two hundred thirty-one million, eleven thousand, two hundred twenty".