231445331 has 6 divisors (see below), whose sum is σ = 250618500. Its totient is φ = 213641688.

The previous prime is 231445321. The next prime is 231445339. The reversal of 231445331 is 133544132.

It is a de Polignac number, because none of the positive numbers 2^k-231445331 is a prime.

It is a super-2 number, since 2×231445331² = 107133882483399122, which contains 22 as substring.

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 231445331.

It is not an unprimeable number, because it can be changed into a prime (231445339) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 684581 + ... + 684918.

It is an arithmetic number, because the mean of its divisors is an integer number (41769750).

Almost surely, 2^231445331 is an apocalyptic number.

231445331 is a deficient number, since it is larger than the sum of its proper divisors (19173169).

231445331 is a wasteful number, since it uses less digits than its factorization.

231445331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1369525 (or 1369512 counting only the distinct ones).

The product of its digits is 4320, while the sum is 26.

The square root of 231445331 is about 15213.3274138171. The cubic root of 231445331 is about 613.9732850264.

Adding to 231445331 its reverse (133544132), we get a palindrome (364989463).

The spelling of 231445331 in words is "two hundred thirty-one million, four hundred forty-five thousand, three hundred thirty-one".