16209989 has 4 divisors (see below), whose sum is σ = 16220160. Its totient is φ = 16199820.

The previous prime is 16209967. The next prime is 16210013. The reversal of 16209989 is 98990261.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 98990261 = 1747 ⋅56663.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16209989 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 (16209889) 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, 2117 + ... + 6074.

It is an arithmetic number, because the mean of its divisors is an integer number (4055040).

Almost surely, 2^16209989 is an apocalyptic number.

It is an amenable number.

16209989 is a deficient number, since it is larger than the sum of its proper divisors (10171).

16209989 is an equidigital number, since it uses as much as digits as its factorization.

16209989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10170.

The product of its (nonzero) digits is 69984, while the sum is 44.

The square root of 16209989 is about 4026.1630617748. The cubic root of 16209989 is about 253.0817953797.

The spelling of 16209989 in words is "sixteen million, two hundred nine thousand, nine hundred eighty-nine".