231332661 has 24 divisors (see below), whose sum is σ = 384011264. Its totient is φ = 131453280.

The previous prime is 231332611. The next prime is 231332663. The reversal of 231332661 is 166233132.

It is a happy number.

It is not a de Polignac number, because 231332661 - 2⁹ = 231332149 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231332663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1260 + ... + 21546.

Almost surely, 2^231332661 is an apocalyptic number.

231332661 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

231332661 is a deficient number, since it is larger than the sum of its proper divisors (152678603).

231332661 is a wasteful number, since it uses less digits than its factorization.

231332661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20481 (or 20478 counting only the distinct ones).

The product of its digits is 3888, while the sum is 27.

The square root of 231332661 is about 15209.6239598486. The cubic root of 231332661 is about 613.8736393231.

Adding to 231332661 its reverse (166233132), we get a palindrome (397565793).

The spelling of 231332661 in words is "two hundred thirty-one million, three hundred thirty-two thousand, six hundred sixty-one".