231888640 has 72 divisors (see below), whose sum is σ = 574691040. Its totient is φ = 89542656.

The previous prime is 231888617. The next prime is 231888641. The reversal of 231888640 is 46888132.

It is a super-2 number, since 2×231888640² = 107544682722099200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 231888593 and 231888602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231888641) 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, 33997 + ... + 40243.

It is an arithmetic number, because the mean of its divisors is an integer number (7981820).

Almost surely, 2^231888640 is an apocalyptic number.

231888640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 231888640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (287345520).

231888640 is an abundant number, since it is smaller than the sum of its proper divisors (342802400).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

231888640 is an equidigital number, since it uses as much as digits as its factorization.

231888640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6297 (or 6283 counting only the distinct ones).

The product of its (nonzero) digits is 73728, while the sum is 40.

The square root of 231888640 is about 15227.8902018632. The cubic root of 231888640 is about 614.3650352643.

The spelling of 231888640 in words is "two hundred thirty-one million, eight hundred eighty-eight thousand, six hundred forty".