231503440 has 120 divisors (see below), whose sum is σ = 635483880. Its totient is φ = 78188544.

The previous prime is 231503431. The next prime is 231503449. The reversal of 231503440 is 44305132.

231503440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (231503431) and next prime (231503449).

It can be written as a sum of positive squares in 4 ways, for example, as 67765824 + 163737616 = 8232^2 + 12796^2 .

It is a nialpdrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231503449) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 285756 + ... + 286564.

It is an arithmetic number, because the mean of its divisors is an integer number (5295699).

Almost surely, 2^231503440 is an apocalyptic number.

231503440 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 231503440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (317741940).

231503440 is an abundant number, since it is smaller than the sum of its proper divisors (403980440).

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

231503440 is a wasteful number, since it uses less digits than its factorization.

231503440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 909 (or 896 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 22.

The square root of 231503440 is about 15215.2370996971. The cubic root of 231503440 is about 614.0246641693.

Adding to 231503440 its reverse (44305132), we get a palindrome (275808572).

The spelling of 231503440 in words is "two hundred thirty-one million, five hundred three thousand, four hundred forty".