18873817 has 4 divisors (see below), whose sum is σ = 19334196. Its totient is φ = 18413440.

The previous prime is 18873797. The next prime is 18873853. The reversal of 18873817 is 71837881.

It is a happy number.

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 802816 + 18071001 = 896^2 + 4251^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18873817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18873887) 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, 230128 + ... + 230209.

It is an arithmetic number, because the mean of its divisors is an integer number (4833549).

Almost surely, 2^18873817 is an apocalyptic number.

It is an amenable number.

18873817 is a deficient number, since it is larger than the sum of its proper divisors (460379).

18873817 is an equidigital number, since it uses as much as digits as its factorization.

18873817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 460378.

The product of its digits is 75264, while the sum is 43.

The square root of 18873817 is about 4344.4006491115. The cubic root of 18873817 is about 266.2481384369.

The spelling of 18873817 in words is "eighteen million, eight hundred seventy-three thousand, eight hundred seventeen".