16659997 has 2 divisors, whose sum is σ = 16659998. Its totient is φ = 16659996.

The previous prime is 16659991. The next prime is 16660013. The reversal of 16659997 is 79995661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14055001 + 2604996 = 3749^2 + 1614^2 .

It is a cyclic number.

It is not a de Polignac number, because 16659997 - 2⁷ = 16659869 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16659991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8329998 + 8329999.

It is an arithmetic number, because the mean of its divisors is an integer number (8329999).

Almost surely, 2^16659997 is an apocalyptic number.

It is an amenable number.

16659997 is a deficient number, since it is larger than the sum of its proper divisors (1).

16659997 is an equidigital number, since it uses as much as digits as its factorization.

16659997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 918540, while the sum is 52.

The square root of 16659997 is about 4081.6659588947. The cubic root of 16659997 is about 255.4023993951.

The spelling of 16659997 in words is "sixteen million, six hundred fifty-nine thousand, nine hundred ninety-seven".