18889399 has 4 divisors (see below), whose sum is σ = 18905040. Its totient is φ = 18873760.

The previous prime is 18889393. The next prime is 18889433. The reversal of 18889399 is 99398881.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99398881 = 17 ⋅5846993.

It is a cyclic number.

It is not a de Polignac number, because 18889399 - 2³ = 18889391 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 (18889391) 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, 5842 + ... + 8479.

It is an arithmetic number, because the mean of its divisors is an integer number (4726260).

Almost surely, 2^18889399 is an apocalyptic number.

18889399 is a deficient number, since it is larger than the sum of its proper divisors (15641).

18889399 is a wasteful number, since it uses less digits than its factorization.

18889399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15640.

The product of its digits is 1119744, while the sum is 55.

The square root of 18889399 is about 4346.1936220100. The cubic root of 18889399 is about 266.3213887200.

The spelling of 18889399 in words is "eighteen million, eight hundred eighty-nine thousand, three hundred ninety-nine".