231820391 has 12 divisors (see below), whose sum is σ = 256454856. Its totient is φ = 209386320.

The previous prime is 231820373. The next prime is 231820417. The reversal of 231820391 is 193028132.

It is not a de Polignac number, because 231820391 - 2⁶ = 231820327 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 (231820991) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12896 + ... + 25098.

It is an arithmetic number, because the mean of its divisors is an integer number (21371238).

Almost surely, 2^231820391 is an apocalyptic number.

231820391 is a deficient number, since it is larger than the sum of its proper divisors (24634465).

231820391 is a wasteful number, since it uses less digits than its factorization.

231820391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12382 (or 12371 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 231820391 is about 15225.6491158834. The cubic root of 231820391 is about 614.3047564547.

The spelling of 231820391 in words is "two hundred thirty-one million, eight hundred twenty thousand, three hundred ninety-one".