231331440 has 80 divisors (see below), whose sum is σ = 722052000. Its totient is φ = 61264896.

The previous prime is 231331439. The next prime is 231331469. The reversal of 231331440 is 44133132.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32526 + ... + 38994.

It is an arithmetic number, because the mean of its divisors is an integer number (9025650).

Almost surely, 2^231331440 is an apocalyptic number.

231331440 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 231331440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (361026000).

231331440 is an abundant number, since it is smaller than the sum of its proper divisors (490720560).

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

231331440 is a wasteful number, since it uses less digits than its factorization.

231331440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6634 (or 6628 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 21.

The square root of 231331440 is about 15209.5838207362. The cubic root of 231331440 is about 613.8725592897.

Adding to 231331440 its reverse (44133132), we get a palindrome (275464572).

The spelling of 231331440 in words is "two hundred thirty-one million, three hundred thirty-one thousand, four hundred forty".