18613889 has 4 divisors (see below), whose sum is σ = 21273024. Its totient is φ = 15954756.

The previous prime is 18613871. The next prime is 18613891. The reversal of 18613889 is 98831681.

It is a happy number.

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 not a de Polignac number, because 18613889 - 2⁸ = 18613633 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18613489) 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, 1329557 + ... + 1329570.

It is an arithmetic number, because the mean of its divisors is an integer number (5318256).

Almost surely, 2^18613889 is an apocalyptic number.

It is an amenable number.

18613889 is a deficient number, since it is larger than the sum of its proper divisors (2659135).

18613889 is an equidigital number, since it uses as much as digits as its factorization.

18613889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2659134.

The product of its digits is 82944, while the sum is 44.

The square root of 18613889 is about 4314.3816474670. The cubic root of 18613889 is about 265.0202381601.

The spelling of 18613889 in words is "eighteen million, six hundred thirteen thousand, eight hundred eighty-nine".