231311616 has 72 divisors (see below), whose sum is σ = 618105600. Its totient is φ = 76793856.

The previous prime is 231311603. The next prime is 231311629. The reversal of 231311616 is 616113132.

It is an interprime number because it is at equal distance from previous prime (231311603) and next prime (231311629).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 267601 + ... + 268463.

It is an arithmetic number, because the mean of its divisors is an integer number (8584800).

Almost surely, 2^231311616 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 231311616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (309052800).

231311616 is an abundant number, since it is smaller than the sum of its proper divisors (386793984).

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

231311616 is an equidigital number, since it uses as much as digits as its factorization.

231311616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1231 (or 1217 counting only the distinct ones).

The product of its digits is 648, while the sum is 24.

The square root of 231311616 is about 15208.9321124134. The cubic root of 231311616 is about 613.8550234729.

Adding to 231311616 its reverse (616113132), we get a palindrome (847424748).

It can be divided in two parts, 2313116 and 16, that added together give a palindrome (2313132).

The spelling of 231311616 in words is "two hundred thirty-one million, three hundred eleven thousand, six hundred sixteen".