16443989 has 4 divisors (see below), whose sum is σ = 16542624. Its totient is φ = 16345356.

The previous prime is 16443979. The next prime is 16443991. The reversal of 16443989 is 98934461.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16443989 is a prime.

It is a super-3 number, since 3×16443989³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16443979) 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, 49067 + ... + 49400.

It is an arithmetic number, because the mean of its divisors is an integer number (4135656).

Almost surely, 2^16443989 is an apocalyptic number.

It is an amenable number.

16443989 is a deficient number, since it is larger than the sum of its proper divisors (98635).

16443989 is an equidigital number, since it uses as much as digits as its factorization.

16443989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98634.

The product of its digits is 186624, while the sum is 44.

The square root of 16443989 is about 4055.1188638559. The cubic root of 16443989 is about 254.2937731829.

The spelling of 16443989 in words is "sixteen million, four hundred forty-three thousand, nine hundred eighty-nine".