231310221 has 8 divisors (see below), whose sum is σ = 308518560. Its totient is φ = 154154352.

The previous prime is 231310213. The next prime is 231310229. The reversal of 231310221 is 122013132.

231310221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (231310213) and next prime (231310229).

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

It is not a de Polignac number, because 231310221 - 2³ = 231310213 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 231310221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231310229) 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, 1311 + ... + 21548.

It is an arithmetic number, because the mean of its divisors is an integer number (38564820).

Almost surely, 2^231310221 is an apocalyptic number.

It is an amenable number.

231310221 is a deficient number, since it is larger than the sum of its proper divisors (77208339).

231310221 is a wasteful number, since it uses less digits than its factorization.

231310221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26235.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 231310221 is about 15208.8862511362. The cubic root of 231310221 is about 613.8537894529.

Adding to 231310221 its reverse (122013132), we get a palindrome (353323353).

The spelling of 231310221 in words is "two hundred thirty-one million, three hundred ten thousand, two hundred twenty-one".