18871859 has 2 divisors, whose sum is σ = 18871860. Its totient is φ = 18871858.

The previous prime is 18871841. The next prime is 18871861. The reversal of 18871859 is 95817881.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18871859 - 2²⁰ = 17823283 is a prime.

It is a super-2 number, since 2×18871859² = 712294124231762, which contains 22 as substring.

Together with 18871861, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18871889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9435929 + 9435930.

It is an arithmetic number, because the mean of its divisors is an integer number (9435930).

Almost surely, 2^18871859 is an apocalyptic number.

18871859 is a deficient number, since it is larger than the sum of its proper divisors (1).

18871859 is an equidigital number, since it uses as much as digits as its factorization.

18871859 is an evil number, because the sum of its binary digits is even.

The product of its digits is 161280, while the sum is 47.

The square root of 18871859 is about 4344.1752957265. The cubic root of 18871859 is about 266.2389311157.

The spelling of 18871859 in words is "eighteen million, eight hundred seventy-one thousand, eight hundred fifty-nine".