16517989 has 4 divisors (see below), whose sum is σ = 16526124. Its totient is φ = 16509856.

The previous prime is 16517983. The next prime is 16518013. The reversal of 16517989 is 98971561.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 14062500 + 2455489 = 3750^2 + 1567^2 .

It is a cyclic number.

It is not a de Polignac number, because 16517989 - 2³ = 16517981 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 (16517981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1809 + ... + 6025.

It is an arithmetic number, because the mean of its divisors is an integer number (4131531).

Almost surely, 2^16517989 is an apocalyptic number.

It is an amenable number.

16517989 is a deficient number, since it is larger than the sum of its proper divisors (8135).

16517989 is an equidigital number, since it uses as much as digits as its factorization.

16517989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8134.

The product of its digits is 136080, while the sum is 46.

The square root of 16517989 is about 4064.2328919490. The cubic root of 16517989 is about 254.6746536409.

The spelling of 16517989 in words is "sixteen million, five hundred seventeen thousand, nine hundred eighty-nine".