231888639 has 4 divisors (see below), whose sum is σ = 309184856. Its totient is φ = 154592424.

The previous prime is 231888617. The next prime is 231888641. The reversal of 231888639 is 936888132.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 231888639 - 2⁵ = 231888607 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 (231888539) 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 3 ways as a sum of consecutive naturals, for example, 38648104 + ... + 38648109.

It is an arithmetic number, because the mean of its divisors is an integer number (77296214).

Almost surely, 2^231888639 is an apocalyptic number.

231888639 is a deficient number, since it is larger than the sum of its proper divisors (77296217).

231888639 is an equidigital number, since it uses as much as digits as its factorization.

231888639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77296216.

The product of its digits is 497664, while the sum is 48.

The square root of 231888639 is about 15227.8901690287. The cubic root of 231888639 is about 614.3650343812.

The spelling of 231888639 in words is "two hundred thirty-one million, eight hundred eighty-eight thousand, six hundred thirty-nine".