18135805 has 8 divisors (see below), whose sum is σ = 22173912. Its totient is φ = 14234688.

The previous prime is 18135791. The next prime is 18135827. The reversal of 18135805 is 50853181.

18135805 = 360² + 361² + ... + 465².

It can be written as a sum of positive squares in 4 ways, for example, as 3892729 + 14243076 = 1973^2 + 3774^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 18135805 - 2⁵ = 18135773 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, 33954 + ... + 34483.

It is an arithmetic number, because the mean of its divisors is an integer number (2771739).

Almost surely, 2^18135805 is an apocalyptic number.

It is an amenable number.

18135805 is a deficient number, since it is larger than the sum of its proper divisors (4038107).

18135805 is an equidigital number, since it uses as much as digits as its factorization.

18135805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68495.

The product of its (nonzero) digits is 4800, while the sum is 31.

The square root of 18135805 is about 4258.6153853101. The cubic root of 18135805 is about 262.7315809725.

Adding to 18135805 its reverse (50853181), we get a palindrome (68988986).

The spelling of 18135805 in words is "eighteen million, one hundred thirty-five thousand, eight hundred five".