18500805 has 24 divisors (see below), whose sum is σ = 33257952. Its totient is φ = 9866448.

The previous prime is 18500803. The next prime is 18500827. The reversal of 18500805 is 50800581.

It is not a de Polignac number, because 18500805 - 2¹ = 18500803 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18500803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6399 + ... + 8828.

It is an arithmetic number, because the mean of its divisors is an integer number (1385748).

Almost surely, 2^18500805 is an apocalyptic number.

18500805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18500805 is a deficient number, since it is larger than the sum of its proper divisors (14757147).

18500805 is an equidigital number, since it uses as much as digits as its factorization.

18500805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15247 (or 15235 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 27.

The square root of 18500805 is about 4301.2562118525. The cubic root of 18500805 is about 264.4824597105.

The spelling of 18500805 in words is "eighteen million, five hundred thousand, eight hundred five".