231916661 has 2 divisors, whose sum is σ = 231916662. Its totient is φ = 231916660.

The previous prime is 231916649. The next prime is 231916667. The reversal of 231916661 is 166619132.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 137710225 + 94206436 = 11735^2 + 9706^2 .

It is a cyclic number.

It is not a de Polignac number, because 231916661 - 2¹⁰ = 231915637 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231916667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115958330 + 115958331.

It is an arithmetic number, because the mean of its divisors is an integer number (115958331).

Almost surely, 2^231916661 is an apocalyptic number.

It is an amenable number.

231916661 is a deficient number, since it is larger than the sum of its proper divisors (1).

231916661 is an equidigital number, since it uses as much as digits as its factorization.

231916661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11664, while the sum is 35.

The square root of 231916661 is about 15228.8102292989. The cubic root of 231916661 is about 614.3897805174.

The spelling of 231916661 in words is "two hundred thirty-one million, nine hundred sixteen thousand, six hundred sixty-one".