18722871 has 12 divisors (see below), whose sum is σ = 27208272. Its totient is φ = 12406176.

The previous prime is 18722867. The next prime is 18722903. The reversal of 18722871 is 17822781.

It is a happy number.

It is not a de Polignac number, because 18722871 - 2² = 18722867 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18722861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4726 + ... + 7731.

It is an arithmetic number, because the mean of its divisors is an integer number (2267356).

Almost surely, 2^18722871 is an apocalyptic number.

18722871 is a deficient number, since it is larger than the sum of its proper divisors (8485401).

18722871 is a wasteful number, since it uses less digits than its factorization.

18722871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12630 (or 12627 counting only the distinct ones).

The product of its digits is 12544, while the sum is 36.

The square root of 18722871 is about 4326.9932978917. The cubic root of 18722871 is about 265.5364521646.

The spelling of 18722871 in words is "eighteen million, seven hundred twenty-two thousand, eight hundred seventy-one".