231405440 has 192 divisors, whose sum is σ = 661400640. Its totient is φ = 77156352.

The previous prime is 231405439. The next prime is 231405451. The reversal of 231405440 is 44504132.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1473842 + ... + 1473998.

It is an arithmetic number, because the mean of its divisors is an integer number (3444795).

Almost surely, 2^231405440 is an apocalyptic number.

231405440 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 231405440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (330700320).

231405440 is an abundant number, since it is smaller than the sum of its proper divisors (429995200).

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

231405440 is a wasteful number, since it uses less digits than its factorization.

231405440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 237 (or 218 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 231405440 is about 15212.0163029100. The cubic root of 231405440 is about 613.9380089989.

Adding to 231405440 its reverse (44504132), we get a palindrome (275909572).

The spelling of 231405440 in words is "two hundred thirty-one million, four hundred five thousand, four hundred forty".