18969889 has 4 divisors (see below), whose sum is σ = 18981424. Its totient is φ = 18958356.

The previous prime is 18969877. The next prime is 18969901. The reversal of 18969889 is 98896981.

18969889 is nontrivially palindromic in base 4.

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.

It is an interprime number because it is at equal distance from previous prime (18969877) and next prime (18969901).

It is a cyclic number.

It is not a de Polignac number, because 18969889 - 2¹³ = 18961697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18969869) 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, 2787 + ... + 6760.

It is an arithmetic number, because the mean of its divisors is an integer number (4745356).

Almost surely, 2^18969889 is an apocalyptic number.

It is an amenable number.

18969889 is a deficient number, since it is larger than the sum of its proper divisors (11535).

18969889 is an equidigital number, since it uses as much as digits as its factorization.

18969889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11534.

The product of its digits is 2239488, while the sum is 58.

The square root of 18969889 is about 4355.4436054207. The cubic root of 18969889 is about 266.6991285135.

The spelling of 18969889 in words is "eighteen million, nine hundred sixty-nine thousand, eight hundred eighty-nine".