231532661 has 2 divisors, whose sum is σ = 231532662. Its totient is φ = 231532660.

The previous prime is 231532619. The next prime is 231532667. The reversal of 231532661 is 166235132.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 195832036 + 35700625 = 13994^2 + 5975^2 .

It is a cyclic number.

It is not a de Polignac number, because 231532661 - 2¹⁰ = 231531637 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 (231532667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115766330 + 115766331.

It is an arithmetic number, because the mean of its divisors is an integer number (115766331).

Almost surely, 2^231532661 is an apocalyptic number.

It is an amenable number.

231532661 is a deficient number, since it is larger than the sum of its proper divisors (1).

231532661 is an equidigital number, since it uses as much as digits as its factorization.

231532661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6480, while the sum is 29.

The square root of 231532661 is about 15216.1973239046. The cubic root of 231532661 is about 614.0504977089.

Adding to 231532661 its reverse (166235132), we get a palindrome (397767793).

The spelling of 231532661 in words is "two hundred thirty-one million, five hundred thirty-two thousand, six hundred sixty-one".