231121320 has 128 divisors (see below), whose sum is σ = 735436800. Its totient is φ = 57943296.

The previous prime is 231121309. The next prime is 231121327. The reversal of 231121320 is 23121132.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 231121320.

It is not an unprimeable number, because it can be changed into a prime (231121327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 380457 + ... + 381063.

It is an arithmetic number, because the mean of its divisors is an integer number (5745600).

Almost surely, 2^231121320 is an apocalyptic number.

231121320 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 231121320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (367718400).

231121320 is an abundant number, since it is smaller than the sum of its proper divisors (504315480).

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

231121320 is a wasteful number, since it uses less digits than its factorization.

231121320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 807 (or 803 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 231121320 is about 15202.6747646590. The cubic root of 231121320 is about 613.6866413774.

Adding to 231121320 its reverse (23121132), we get a palindrome (254242452).

The spelling of 231121320 in words is "two hundred thirty-one million, one hundred twenty-one thousand, three hundred twenty".