16689917 has 8 divisors (see below), whose sum is σ = 17100216. Its totient is φ = 16284672.

The previous prime is 16689913. The next prime is 16689919. The reversal of 16689917 is 71998661.

It can be written as a sum of positive squares in 4 ways, for example, as 857476 + 15832441 = 926^2 + 3979^2 .

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 16689917 - 2² = 16689913 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 (16689913) 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, 5903 + ... + 8259.

It is an arithmetic number, because the mean of its divisors is an integer number (2137527).

Almost surely, 2^16689917 is an apocalyptic number.

It is an amenable number.

16689917 is a deficient number, since it is larger than the sum of its proper divisors (410299).

16689917 is an equidigital number, since it uses as much as digits as its factorization.

16689917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2527.

The product of its digits is 163296, while the sum is 47.

The square root of 16689917 is about 4085.3294848763. The cubic root of 16689917 is about 255.5552019389. Note that the first 3 decimals are identical.

The spelling of 16689917 in words is "sixteen million, six hundred eighty-nine thousand, nine hundred seventeen".