231695640 has 288 divisors, whose sum is σ = 862701840. Its totient is φ = 55883520.

The previous prime is 231695623. The next prime is 231695641. The reversal of 231695640 is 46596132.

It is a happy number.

231695640 is a `hidden beast` number, since 2 + 3 + 1 + 6 + 9 + 5 + 640 = 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 = 231695595 and 231695604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231695641) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1176022 + ... + 1176218.

Almost surely, 2^231695640 is an apocalyptic number.

231695640 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 231695640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (431350920).

231695640 is an abundant number, since it is smaller than the sum of its proper divisors (631006200).

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

231695640 is a wasteful number, since it uses less digits than its factorization.

231695640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245 (or 218 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 231695640 is about 15221.5518262758. The cubic root of 231695640 is about 614.1945434242.

The spelling of 231695640 in words is "two hundred thirty-one million, six hundred ninety-five thousand, six hundred forty".