16643799 has 42 divisors (see below), whose sum is σ = 26844080. Its totient is φ = 10310976.

The previous prime is 16643779. The next prime is 16643839. The reversal of 16643799 is 99734661.

It is not a de Polignac number, because 16643799 - 2⁹ = 16643287 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 (16643729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 41 ways as a sum of consecutive naturals, for example, 210642 + ... + 210720.

Almost surely, 2^16643799 is an apocalyptic number.

16643799 is a deficient number, since it is larger than the sum of its proper divisors (10200281).

16643799 is an frugal number, since it uses more digits than its factorization.

16643799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131 (or 99 counting only the distinct ones).

The product of its digits is 244944, while the sum is 45.

The square root of 16643799 is about 4079.6812375479. The cubic root of 16643799 is about 255.3195992692.

The spelling of 16643799 in words is "sixteen million, six hundred forty-three thousand, seven hundred ninety-nine".