18400273 has 4 divisors (see below), whose sum is σ = 19482660. Its totient is φ = 17317888.

The previous prime is 18400247. The next prime is 18400301. The reversal of 18400273 is 37200481.

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

It can be written as a sum of positive squares in 2 ways, for example, as 13786369 + 4613904 = 3713^2 + 2148^2 .

It is a cyclic number.

It is not a de Polignac number, because 18400273 - 2⁵ = 18400241 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, 541168 + ... + 541201.

It is an arithmetic number, because the mean of its divisors is an integer number (4870665).

Almost surely, 2^18400273 is an apocalyptic number.

It is an amenable number.

18400273 is a deficient number, since it is larger than the sum of its proper divisors (1082387).

18400273 is a wasteful number, since it uses less digits than its factorization.

18400273 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1082386.

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 18400273 is about 4289.5539395140. The cubic root of 18400273 is about 264.0025300110.

The spelling of 18400273 in words is "eighteen million, four hundred thousand, two hundred seventy-three".