16689999 has 8 divisors (see below), whose sum is σ = 23424640. Its totient is φ = 10541016.

The previous prime is 16689941. The next prime is 16690001. The reversal of 16689999 is 99998661.

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

It is a de Polignac number, because none of the positive numbers 2^k-16689999 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57), and also a Moran number because the ratio is a prime number: 292807 = 16689999 / (1 + 6 + 6 + 8 + 9 + 9 + 9 + 9).

It is a Duffinian number.

16689999 is a modest number, since divided by 9999 gives 1668 as remainder.

It is a plaindrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16689919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 146347 + ... + 146460.

It is an arithmetic number, because the mean of its divisors is an integer number (2928080).

Almost surely, 2^16689999 is an apocalyptic number.

16689999 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

16689999 is a deficient number, since it is larger than the sum of its proper divisors (6734641).

16689999 is a wasteful number, since it uses less digits than its factorization.

16689999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292829.

The product of its digits is 1889568, while the sum is 57.

The square root of 16689999 is about 4085.3395207743. The cubic root of 16689999 is about 255.5556204649. Note that the first 3 decimals are identical.

The spelling of 16689999 in words is "sixteen million, six hundred eighty-nine thousand, nine hundred ninety-nine".