16688399 has 8 divisors (see below), whose sum is σ = 20539680. Its totient is φ = 13203936.

The previous prime is 16688389. The next prime is 16688411. The reversal of 16688399 is 99388661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 16688399 - 2¹⁶ = 16622863 is a prime.

It is a super-2 number, since 2×16688399² = 557005322366402, which contains 22 as substring.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16688389) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 91604 + ... + 91785.

It is an arithmetic number, because the mean of its divisors is an integer number (2567460).

Almost surely, 2^16688399 is an apocalyptic number.

16688399 is a deficient number, since it is larger than the sum of its proper divisors (3851281).

16688399 is a wasteful number, since it uses less digits than its factorization.

16688399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183409.

The product of its digits is 559872, while the sum is 50.

The square root of 16688399 is about 4085.1436939231. The cubic root of 16688399 is about 255.5474538564.

The spelling of 16688399 in words is "sixteen million, six hundred eighty-eight thousand, three hundred ninety-nine".