231320987 has 4 divisors (see below), whose sum is σ = 231373296. Its totient is φ = 231268680.

The previous prime is 231320939. The next prime is 231321001. The reversal of 231320987 is 789023132.

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 231320987 - 2⁸ = 231320731 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231320587) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18839 + ... + 28592.

It is an arithmetic number, because the mean of its divisors is an integer number (57843324).

Almost surely, 2^231320987 is an apocalyptic number.

231320987 is a deficient number, since it is larger than the sum of its proper divisors (52309).

231320987 is an equidigital number, since it uses as much as digits as its factorization.

231320987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52308.

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 231320987 is about 15209.2401848350. The cubic root of 231320987 is about 613.8633129510.

The spelling of 231320987 in words is "two hundred thirty-one million, three hundred twenty thousand, nine hundred eighty-seven".