231372221 has 2 divisors, whose sum is σ = 231372222. Its totient is φ = 231372220.

The previous prime is 231372209. The next prime is 231372233. The reversal of 231372221 is 122273132.

It is a balanced prime because it is at equal distance from previous prime (231372209) and next prime (231372233).

It can be written as a sum of positive squares in only one way, i.e., 216825625 + 14546596 = 14725^2 + 3814^2 .

It is a cyclic number.

It is not a de Polignac number, because 231372221 - 2²² = 227177917 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231372521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115686110 + 115686111.

It is an arithmetic number, because the mean of its divisors is an integer number (115686111).

Almost surely, 2^231372221 is an apocalyptic number.

It is an amenable number.

231372221 is a deficient number, since it is larger than the sum of its proper divisors (1).

231372221 is an equidigital number, since it uses as much as digits as its factorization.

231372221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1008, while the sum is 23.

The square root of 231372221 is about 15210.9243966302. The cubic root of 231372221 is about 613.9086299968.

The spelling of 231372221 in words is "two hundred thirty-one million, three hundred seventy-two thousand, two hundred twenty-one".