16688409 has 8 divisors (see below), whose sum is σ = 23218752. Its totient is φ = 10641840.

The previous prime is 16688389. The next prime is 16688411. The reversal of 16688409 is 90488661.

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

It is not a de Polignac number, because 16688409 - 2⁵ = 16688377 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16688449) 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, 120862 + ... + 120999.

It is an arithmetic number, because the mean of its divisors is an integer number (2902344).

Almost surely, 2^16688409 is an apocalyptic number.

It is an amenable number.

16688409 is a deficient number, since it is larger than the sum of its proper divisors (6530343).

16688409 is a wasteful number, since it uses less digits than its factorization.

16688409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241887.

The product of its (nonzero) digits is 82944, while the sum is 42.

The square root of 16688409 is about 4085.1449178701. The cubic root of 16688409 is about 255.5475048994.

The spelling of 16688409 in words is "sixteen million, six hundred eighty-eight thousand, four hundred nine".