231693991 has 8 divisors (see below), whose sum is σ = 233319920. Its totient is φ = 230072832.

The previous prime is 231693983. The next prime is 231694007. The reversal of 231693991 is 199396132.

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 231693991 - 2³ = 231693983 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 (231693941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 205756 + ... + 206878.

It is an arithmetic number, because the mean of its divisors is an integer number (29164990).

Almost surely, 2^231693991 is an apocalyptic number.

231693991 is a deficient number, since it is larger than the sum of its proper divisors (1625929).

231693991 is a wasteful number, since it uses less digits than its factorization.

231693991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2385.

The product of its digits is 78732, while the sum is 43.

The square root of 231693991 is about 15221.4976595603. The cubic root of 231693991 is about 614.1930863270.

The spelling of 231693991 in words is "two hundred thirty-one million, six hundred ninety-three thousand, nine hundred ninety-one".