231540540 has 192 divisors, whose sum is σ = 843816960. Its totient is φ = 45999360.

The previous prime is 231540523. The next prime is 231540557. The reversal of 231540540 is 45045132.

It is an interprime number because it is at equal distance from previous prime (231540523) and next prime (231540557).

It is a super-2 number, since 2×231540540² = 107222043326983200, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 231540540.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 105171 + ... + 107349.

It is an arithmetic number, because the mean of its divisors is an integer number (4394880).

Almost surely, 2^231540540 is an apocalyptic number.

231540540 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 231540540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (421908480).

231540540 is an abundant number, since it is smaller than the sum of its proper divisors (612276420).

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

231540540 is a wasteful number, since it uses less digits than its factorization.

231540540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2232 (or 2230 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 24.

The square root of 231540540 is about 15216.4562234444. The cubic root of 231540540 is about 614.0574629594.

Adding to 231540540 its reverse (45045132), we get a palindrome (276585672).

The spelling of 231540540 in words is "two hundred thirty-one million, five hundred forty thousand, five hundred forty".