16231661 has 2 divisors, whose sum is σ = 16231662. Its totient is φ = 16231660.

The previous prime is 16231639. The next prime is 16231669. The reversal of 16231661 is 16613261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10562500 + 5669161 = 3250^2 + 2381^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16231661 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16231661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16231669) 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 as a sum of consecutive naturals, namely, 8115830 + 8115831.

It is an arithmetic number, because the mean of its divisors is an integer number (8115831).

Almost surely, 2^16231661 is an apocalyptic number.

It is an amenable number.

16231661 is a deficient number, since it is larger than the sum of its proper divisors (1).

16231661 is an equidigital number, since it uses as much as digits as its factorization.

16231661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1296, while the sum is 26.

The square root of 16231661 is about 4028.8535590165. The cubic root of 16231661 is about 253.1945313431.

The spelling of 16231661 in words is "sixteen million, two hundred thirty-one thousand, six hundred sixty-one".