16509009 has 16 divisors (see below), whose sum is σ = 25058304. Its totient is φ = 9570000.

The previous prime is 16508983. The next prime is 16509011. The reversal of 16509009 is 90090561.

It is not a de Polignac number, because 16509009 - 2⁵ = 16508977 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16509089) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10117 + ... + 11634.

It is an arithmetic number, because the mean of its divisors is an integer number (1566144).

Almost surely, 2^16509009 is an apocalyptic number.

It is an amenable number.

16509009 is a deficient number, since it is larger than the sum of its proper divisors (8549295).

16509009 is a wasteful number, since it uses less digits than its factorization.

16509009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21788.

The product of its (nonzero) digits is 2430, while the sum is 30.

The square root of 16509009 is about 4063.1279822324. The cubic root of 16509009 is about 254.6284940074.

The spelling of 16509009 in words is "sixteen million, five hundred nine thousand, nine".