18999869 has 8 divisors (see below), whose sum is σ = 22414848. Its totient is φ = 15760080.

The previous prime is 18999839. The next prime is 18999889. The reversal of 18999869 is 96899981.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18999869 - 2²⁴ = 2222653 is a prime.

It is a super-2 number, since 2×18999869² = 721990044034322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18999839) 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 7 ways as a sum of consecutive naturals, for example, 43562 + ... + 43995.

It is an arithmetic number, because the mean of its divisors is an integer number (2801856).

Almost surely, 2^18999869 is an apocalyptic number.

It is an amenable number.

18999869 is a deficient number, since it is larger than the sum of its proper divisors (3414979).

18999869 is an equidigital number, since it uses as much as digits as its factorization.

18999869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87595.

The product of its digits is 2519424, while the sum is 59.

The square root of 18999869 is about 4358.8839167842. The cubic root of 18999869 is about 266.8395516065.

The spelling of 18999869 in words is "eighteen million, nine hundred ninety-nine thousand, eight hundred sixty-nine".