16639589 has 4 divisors (see below), whose sum is σ = 16786956. Its totient is φ = 16492224.

The previous prime is 16639561. The next prime is 16639607. The reversal of 16639589 is 98593661.

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 902500 + 15737089 = 950^2 + 3967^2 .

It is a cyclic number.

It is not a de Polignac number, because 16639589 - 2⁸ = 16639333 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16639559) 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, 73514 + ... + 73739.

It is an arithmetic number, because the mean of its divisors is an integer number (4196739).

Almost surely, 2^16639589 is an apocalyptic number.

It is an amenable number.

16639589 is a deficient number, since it is larger than the sum of its proper divisors (147367).

16639589 is a wasteful number, since it uses less digits than its factorization.

16639589 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147366.

The product of its digits is 349920, while the sum is 47.

The square root of 16639589 is about 4079.1652332309. The cubic root of 16639589 is about 255.2980700066.

The spelling of 16639589 in words is "sixteen million, six hundred thirty-nine thousand, five hundred eighty-nine".