16993309 has 2 divisors, whose sum is σ = 16993310. Its totient is φ = 16993308.

The previous prime is 16993289. The next prime is 16993313. The reversal of 16993309 is 90339961.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13764100 + 3229209 = 3710^2 + 1797^2 .

It is a cyclic number.

It is not a de Polignac number, because 16993309 - 2¹⁹ = 16469021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16993349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8496654 + 8496655.

It is an arithmetic number, because the mean of its divisors is an integer number (8496655).

Almost surely, 2^16993309 is an apocalyptic number.

It is an amenable number.

16993309 is a deficient number, since it is larger than the sum of its proper divisors (1).

16993309 is an equidigital number, since it uses as much as digits as its factorization.

16993309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 39366, while the sum is 40.

The square root of 16993309 is about 4122.2941428287. The cubic root of 16993309 is about 257.0944204329.

The spelling of 16993309 in words is "sixteen million, nine hundred ninety-three thousand, three hundred nine".