16663399 has 12 divisors (see below), whose sum is σ = 18166080. Its totient is φ = 15266880.

The previous prime is 16663397. The next prime is 16663421. The reversal of 16663399 is 99336661.

It is not a de Polignac number, because 16663399 - 2¹ = 16663397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16663393) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10447 + ... + 11935.

It is an arithmetic number, because the mean of its divisors is an integer number (1513840).

Almost surely, 2^16663399 is an apocalyptic number.

16663399 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

16663399 is a deficient number, since it is larger than the sum of its proper divisors (1502681).

16663399 is a wasteful number, since it uses less digits than its factorization.

16663399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1558 (or 1539 counting only the distinct ones).

The product of its digits is 157464, while the sum is 43.

The square root of 16663399 is about 4082.0826792215. The cubic root of 16663399 is about 255.4197827482.

The spelling of 16663399 in words is "sixteen million, six hundred sixty-three thousand, three hundred ninety-nine".