16689405 has 16 divisors (see below), whose sum is σ = 27425664. Its totient is φ = 8660160.

The previous prime is 16689401. The next prime is 16689437. The reversal of 16689405 is 50498661.

It is not a de Polignac number, because 16689405 - 2² = 16689401 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16689401) 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 15 ways as a sum of consecutive naturals, for example, 14481 + ... + 15590.

It is an arithmetic number, because the mean of its divisors is an integer number (1714104).

Almost surely, 2^16689405 is an apocalyptic number.

16689405 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

16689405 is a deficient number, since it is larger than the sum of its proper divisors (10736259).

16689405 is a wasteful number, since it uses less digits than its factorization.

16689405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30116.

The product of its (nonzero) digits is 51840, while the sum is 39.

The square root of 16689405 is about 4085.2668211513. The cubic root of 16689405 is about 255.5525886724.

The spelling of 16689405 in words is "sixteen million, six hundred eighty-nine thousand, four hundred five".