16908989 has 4 divisors (see below), whose sum is σ = 16923324. Its totient is φ = 16894656.

The previous prime is 16908977. The next prime is 16909027. The reversal of 16908989 is 98980961.

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

It can be written as a sum of positive squares in 2 ways, for example, as 15132100 + 1776889 = 3890^2 + 1333^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16908989 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 (16908949) 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, 5222 + ... + 7815.

It is an arithmetic number, because the mean of its divisors is an integer number (4230831).

Almost surely, 2^16908989 is an apocalyptic number.

It is an amenable number.

16908989 is a deficient number, since it is larger than the sum of its proper divisors (14335).

16908989 is a wasteful number, since it uses less digits than its factorization.

16908989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14334.

The product of its (nonzero) digits is 279936, while the sum is 50.

The square root of 16908989 is about 4112.0541095662. The cubic root of 16908989 is about 256.6684850230.

The spelling of 16908989 in words is "sixteen million, nine hundred eight thousand, nine hundred eighty-nine".