16889581 has 4 divisors (see below), whose sum is σ = 17301564. Its totient is φ = 16477600.

The previous prime is 16889573. The next prime is 16889599. The reversal of 16889581 is 18598861.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18598861 = 3169 ⋅5869.

It can be written as a sum of positive squares in 2 ways, for example, as 6456681 + 10432900 = 2541^2 + 3230^2 .

It is a cyclic number.

It is not a de Polignac number, because 16889581 - 2³ = 16889573 is a prime.

It is a super-2 number, since 2×16889581² = 570515892711122, which contains 22 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 (16881581) 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, 205930 + ... + 206011.

It is an arithmetic number, because the mean of its divisors is an integer number (4325391).

Almost surely, 2^16889581 is an apocalyptic number.

It is an amenable number.

16889581 is a deficient number, since it is larger than the sum of its proper divisors (411983).

16889581 is an equidigital number, since it uses as much as digits as its factorization.

16889581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 411982.

The product of its digits is 138240, while the sum is 46.

The square root of 16889581 is about 4109.6935408860. The cubic root of 16889581 is about 256.5702467614.

The spelling of 16889581 in words is "sixteen million, eight hundred eighty-nine thousand, five hundred eighty-one".