231319993 has 4 divisors (see below), whose sum is σ = 241377408. Its totient is φ = 221262580.

The previous prime is 231319987. The next prime is 231320009. The reversal of 231319993 is 399913132.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-231319993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231319903) 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, 5028673 + ... + 5028718.

It is an arithmetic number, because the mean of its divisors is an integer number (60344352).

Almost surely, 2^231319993 is an apocalyptic number.

231319993 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

231319993 is a deficient number, since it is larger than the sum of its proper divisors (10057415).

231319993 is a wasteful number, since it uses less digits than its factorization.

231319993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10057414.

The product of its digits is 39366, while the sum is 40.

The square root of 231319993 is about 15209.2075072964. The cubic root of 231319993 is about 613.8624336807.

It can be divided in two parts, 23131 and 9993, that added together give a square (33124 = 182²).

The spelling of 231319993 in words is "two hundred thirty-one million, three hundred nineteen thousand, nine hundred ninety-three".