231431987 has 8 divisors (see below), whose sum is σ = 235489392. Its totient is φ = 227383200.

The previous prime is 231431983. The next prime is 231432007. The reversal of 231431987 is 789134132.

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 231431987 - 2² = 231431983 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 231431987.

It is not an unprimeable number, because it can be changed into a prime (231431983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 76412 + ... + 79382.

It is an arithmetic number, because the mean of its divisors is an integer number (29436174).

Almost surely, 2^231431987 is an apocalyptic number.

231431987 is a deficient number, since it is larger than the sum of its proper divisors (4057405).

231431987 is a wasteful number, since it uses less digits than its factorization.

231431987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4309.

The product of its digits is 36288, while the sum is 38.

The square root of 231431987 is about 15212.8888446606. Note that the first 4 decimals coincide. The cubic root of 231431987 is about 613.9614852392.

The spelling of 231431987 in words is "two hundred thirty-one million, four hundred thirty-one thousand, nine hundred eighty-seven".