231205665 has 24 divisors (see below), whose sum is σ = 373875264. Its totient is φ = 122008000.

The previous prime is 231205649. The next prime is 231205669. The reversal of 231205665 is 566502132.

It is not a de Polignac number, because 231205665 - 2⁴ = 231205649 is a prime.

It is not an unprimeable number, because it can be changed into a prime (231205669) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 152260 + ... + 153770.

It is an arithmetic number, because the mean of its divisors is an integer number (15578136).

Almost surely, 2^231205665 is an apocalyptic number.

It is an amenable number.

231205665 is a deficient number, since it is larger than the sum of its proper divisors (142669599).

231205665 is a wasteful number, since it uses less digits than its factorization.

231205665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1721 (or 1620 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 30.

The square root of 231205665 is about 15205.4485300500. The cubic root of 231205665 is about 613.7612848654.

Adding to 231205665 its reverse (566502132), we get a palindrome (797707797).

The spelling of 231205665 in words is "two hundred thirty-one million, two hundred five thousand, six hundred sixty-five".