18405073 has 4 divisors (see below), whose sum is σ = 18413748. Its totient is φ = 18396400.

The previous prime is 18405061. The next prime is 18405089. The reversal of 18405073 is 37050481.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 37050481 = 13 ⋅2850037.

It can be written as a sum of positive squares in 2 ways, for example, as 9690769 + 8714304 = 3113^2 + 2952^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18405073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18400073) 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, 1215 + ... + 6187.

It is an arithmetic number, because the mean of its divisors is an integer number (4603437).

Almost surely, 2^18405073 is an apocalyptic number.

It is an amenable number.

18405073 is a deficient number, since it is larger than the sum of its proper divisors (8675).

18405073 is an equidigital number, since it uses as much as digits as its factorization.

18405073 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8674.

The product of its (nonzero) digits is 3360, while the sum is 28.

The square root of 18405073 is about 4290.1134017646. The cubic root of 18405073 is about 264.0254844162.

The spelling of 18405073 in words is "eighteen million, four hundred five thousand, seventy-three".