231643665 has 64 divisors (see below), whose sum is σ = 451526400. Its totient is φ = 111744000.

The previous prime is 231643631. The next prime is 231643669. The reversal of 231643665 is 566346132.

231643665 is a `hidden beast` number, since 2 + 3 + 1 + 643 + 6 + 6 + 5 = 666.

231643665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 231643665 - 2⁸ = 231643409 is a prime.

It is not an unprimeable number, because it can be changed into a prime (231643669) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 577465 + ... + 577865.

It is an arithmetic number, because the mean of its divisors is an integer number (7055100).

Almost surely, 2^231643665 is an apocalyptic number.

It is an amenable number.

231643665 is a deficient number, since it is larger than the sum of its proper divisors (219882735).

231643665 is a wasteful number, since it uses less digits than its factorization.

231643665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 815 (or 809 counting only the distinct ones).

The product of its digits is 77760, while the sum is 36.

The square root of 231643665 is about 15219.8444472997. The cubic root of 231643665 is about 614.1486137026.

Adding to 231643665 its reverse (566346132), we get a palindrome (797989797).

The spelling of 231643665 in words is "two hundred thirty-one million, six hundred forty-three thousand, six hundred sixty-five".