18864839 has 4 divisors (see below), whose sum is σ = 21559824. Its totient is φ = 16169856.

The previous prime is 18864827. The next prime is 18864841. The reversal of 18864839 is 93846881.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18864839 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18864793 and 18864802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18864809) 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, 1347482 + ... + 1347495.

It is an arithmetic number, because the mean of its divisors is an integer number (5389956).

Almost surely, 2^18864839 is an apocalyptic number.

18864839 is a deficient number, since it is larger than the sum of its proper divisors (2694985).

18864839 is an equidigital number, since it uses as much as digits as its factorization.

18864839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2694984.

The product of its digits is 331776, while the sum is 47.

The square root of 18864839 is about 4343.3672421291. The cubic root of 18864839 is about 266.2059149533.

The spelling of 18864839 in words is "eighteen million, eight hundred sixty-four thousand, eight hundred thirty-nine".