231431621 has 8 divisors (see below), whose sum is σ = 237656664. Its totient is φ = 225285120.

The previous prime is 231431597. The next prime is 231431623. The reversal of 231431621 is 126134132.

It can be written as a sum of positive squares in 4 ways, for example, as 4778596 + 226653025 = 2186^2 + 15055^2 .

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 231431621 - 2²⁶ = 164322757 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231431623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13640 + ... + 25473.

It is an arithmetic number, because the mean of its divisors is an integer number (29707083).

Almost surely, 2^231431621 is an apocalyptic number.

It is an amenable number.

231431621 is a deficient number, since it is larger than the sum of its proper divisors (6225043).

231431621 is an equidigital number, since it uses as much as digits as its factorization.

231431621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39271.

The product of its digits is 864, while the sum is 23.

The square root of 231431621 is about 15212.8768153824. The cubic root of 231431621 is about 613.9611615875.

Adding to 231431621 its reverse (126134132), we get a palindrome (357565753).

The spelling of 231431621 in words is "two hundred thirty-one million, four hundred thirty-one thousand, six hundred twenty-one".