221312232 has 48 divisors (see below), whose sum is σ = 604131840. Its totient is φ = 73186848.

The previous prime is 221312191. The next prime is 221312243. The reversal of 221312232 is 232213122.

221312232 is digitally balanced in base 2 and base 3, because in such bases 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 (18).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2958 + ... + 21245.

It is an arithmetic number, because the mean of its divisors is an integer number (12586080).

Almost surely, 2^221312232 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221312232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (302065920).

221312232 is an abundant number, since it is smaller than the sum of its proper divisors (382819608).

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

221312232 is a wasteful number, since it uses less digits than its factorization.

221312232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24342 (or 24335 counting only the distinct ones).

The product of its digits is 288, while the sum is 18.

The square root of 221312232 is about 14876.5665393598. The cubic root of 221312232 is about 604.8789521730.

Adding to 221312232 its reverse (232213122), we get a palindrome (453525354).

The spelling of 221312232 in words is "two hundred twenty-one million, three hundred twelve thousand, two hundred thirty-two".