231387840 has 280 divisors, whose sum is σ = 840882240. Its totient is φ = 60383232.

The previous prime is 231387829. The next prime is 231387841. The reversal of 231387840 is 48783132.

231387840 is a `hidden beast` number, since 231 + 387 + 8 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 231387795 and 231387804.

It is not an unprimeable number, because it can be changed into a prime (231387841) by changing a digit.

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 39 ways as a sum of consecutive naturals, for example, 2047624 + ... + 2047736.

Almost surely, 2^231387840 is an apocalyptic number.

231387840 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 231387840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (420441120).

231387840 is an abundant number, since it is smaller than the sum of its proper divisors (609494400).

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

231387840 is a wasteful number, since it uses less digits than its factorization.

231387840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221 (or 202 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 231387840 is about 15211.4378018648. The cubic root of 231387840 is about 613.9224438464.

The spelling of 231387840 in words is "two hundred thirty-one million, three hundred eighty-seven thousand, eight hundred forty".