18439805 has 8 divisors (see below), whose sum is σ = 22163544. Its totient is φ = 14728000.

The previous prime is 18439787. The next prime is 18439829. The reversal of 18439805 is 50893481.

It can be written as a sum of positive squares in 4 ways, for example, as 6791236 + 11648569 = 2606^2 + 3413^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18439805 - 2¹⁴ = 18423421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 875 + ... + 6135.

It is an arithmetic number, because the mean of its divisors is an integer number (2770443).

Almost surely, 2^18439805 is an apocalyptic number.

It is an amenable number.

18439805 is a deficient number, since it is larger than the sum of its proper divisors (3723739).

18439805 is an equidigital number, since it uses as much as digits as its factorization.

18439805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5967.

The product of its (nonzero) digits is 34560, while the sum is 38.

The square root of 18439805 is about 4294.1594055182. The cubic root of 18439805 is about 264.1914598673.

The spelling of 18439805 in words is "eighteen million, four hundred thirty-nine thousand, eight hundred five".