231132221 has 8 divisors (see below), whose sum is σ = 255369024. Its totient is φ = 208077760.

The previous prime is 231132217. The next prime is 231132257. The reversal of 231132221 is 122231132.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 231132221 - 2² = 231132217 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 231132221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231132271) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 295175 + ... + 295956.

It is an arithmetic number, because the mean of its divisors is an integer number (31921128).

Almost surely, 2^231132221 is an apocalyptic number.

It is an amenable number.

231132221 is a deficient number, since it is larger than the sum of its proper divisors (24236803).

231132221 is a wasteful number, since it uses less digits than its factorization.

231132221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 591171.

The product of its digits is 144, while the sum is 17.

The square root of 231132221 is about 15203.0332828683. The cubic root of 231132221 is about 613.6962895467.

Adding to 231132221 its reverse (122231132), we get a palindrome (353363353).

The spelling of 231132221 in words is "two hundred thirty-one million, one hundred thirty-two thousand, two hundred twenty-one".