231542321 has 4 divisors (see below), whose sum is σ = 232045044. Its totient is φ = 231039600.

The previous prime is 231542309. The next prime is 231542323. The reversal of 231542321 is 123245132.

231542321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 108576400 + 122965921 = 10420^2 + 11089^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-231542321 is a prime.

It is a super-2 number, since 2×231542321² = 107223692828134082, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231542323) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 250670 + ... + 251591.

It is an arithmetic number, because the mean of its divisors is an integer number (58011261).

Almost surely, 2^231542321 is an apocalyptic number.

It is an amenable number.

231542321 is a deficient number, since it is larger than the sum of its proper divisors (502723).

231542321 is an equidigital number, since it uses as much as digits as its factorization.

231542321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 502722.

The product of its digits is 1440, while the sum is 23.

The square root of 231542321 is about 15216.5147454994. The cubic root of 231542321 is about 614.0590373900.

Adding to 231542321 its reverse (123245132), we get a palindrome (354787453).

The spelling of 231542321 in words is "two hundred thirty-one million, five hundred forty-two thousand, three hundred twenty-one".