16688687 has 4 divisors (see below), whose sum is σ = 17076840. Its totient is φ = 16300536.

The previous prime is 16688677. The next prime is 16688701. The reversal of 16688687 is 78688661.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 16688687 - 2²⁰ = 15640111 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 (16688627) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 194012 + ... + 194097.

It is an arithmetic number, because the mean of its divisors is an integer number (4269210).

Almost surely, 2^16688687 is an apocalyptic number.

16688687 is a deficient number, since it is larger than the sum of its proper divisors (388153).

16688687 is an equidigital number, since it uses as much as digits as its factorization.

16688687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 388152.

The product of its digits is 774144, while the sum is 50.

The square root of 16688687 is about 4085.1789434491. The cubic root of 16688687 is about 255.5489238845.

The spelling of 16688687 in words is "sixteen million, six hundred eighty-eight thousand, six hundred eighty-seven".