231131440 has 40 divisors (see below), whose sum is σ = 546201648. Its totient is φ = 90935040.

The previous prime is 231131429. The next prime is 231131471. The reversal of 231131440 is 44131132.

It is a tau number, because it is divible by the number of its divisors (40).

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 18802 + ... + 28561.

Almost surely, 2^231131440 is an apocalyptic number.

231131440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

231131440 is an abundant number, since it is smaller than the sum of its proper divisors (315070208).

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

231131440 is a wasteful number, since it uses less digits than its factorization.

231131440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47437 (or 47431 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 231131440 is about 15203.0075971829. The cubic root of 231131440 is about 613.6955983156.

Adding to 231131440 its reverse (44131132), we get a palindrome (275262572).

The spelling of 231131440 in words is "two hundred thirty-one million, one hundred thirty-one thousand, four hundred forty".