231231643 has 4 divisors (see below), whose sum is σ = 232895320. Its totient is φ = 229567968.

The previous prime is 231231613. The next prime is 231231731. The reversal of 231231643 is 346132132.

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

It is a cyclic number.

It is not a de Polignac number, because 231231643 - 2⁹ = 231231131 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231231613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 831630 + ... + 831907.

It is an arithmetic number, because the mean of its divisors is an integer number (58223830).

Almost surely, 2^231231643 is an apocalyptic number.

231231643 is a deficient number, since it is larger than the sum of its proper divisors (1663677).

231231643 is a wasteful number, since it uses less digits than its factorization.

231231643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1663676.

The product of its digits is 2592, while the sum is 25.

The square root of 231231643 is about 15206.3027393249. The cubic root of 231231643 is about 613.7842711729.

Adding to 231231643 its reverse (346132132), we get a palindrome (577363775).

The spelling of 231231643 in words is "two hundred thirty-one million, two hundred thirty-one thousand, six hundred forty-three".