16791661 has 2 divisors, whose sum is σ = 16791662. Its totient is φ = 16791660.

The previous prime is 16791659. The next prime is 16791703. The reversal of 16791661 is 16619761.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14969161 + 1822500 = 3869^2 + 1350^2 .

It is a cyclic number.

It is not a de Polignac number, because 16791661 - 2¹ = 16791659 is a prime.

Together with 16791659, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 16791661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16791601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8395830 + 8395831.

It is an arithmetic number, because the mean of its divisors is an integer number (8395831).

Almost surely, 2^16791661 is an apocalyptic number.

It is an amenable number.

16791661 is a deficient number, since it is larger than the sum of its proper divisors (1).

16791661 is an equidigital number, since it uses as much as digits as its factorization.

16791661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13608, while the sum is 37.

The square root of 16791661 is about 4097.7629262806. The cubic root of 16791661 is about 256.0734499935.

The spelling of 16791661 in words is "sixteen million, seven hundred ninety-one thousand, six hundred sixty-one".