231222220 has 48 divisors (see below), whose sum is σ = 524180160. Its totient is φ = 85412096.

The previous prime is 231222209. The next prime is 231222259. The reversal of 231222220 is 22222132.

231222220 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 231222194 and 231222203.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4674 + ... + 22006.

It is an arithmetic number, because the mean of its divisors is an integer number (10920420).

Almost surely, 2^231222220 is an apocalyptic number.

231222220 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 231222220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (262090080).

231222220 is an abundant number, since it is smaller than the sum of its proper divisors (292957940).

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

231222220 is a wasteful number, since it uses less digits than its factorization.

231222220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17394 (or 17392 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 231222220 is about 15205.9928975388. The cubic root of 231222220 is about 613.7759335486.

Adding to 231222220 its reverse (22222132), we get a palindrome (253444352).

The spelling of 231222220 in words is "two hundred thirty-one million, two hundred twenty-two thousand, two hundred twenty".