18916785887 has 4 divisors (see below), whose sum is σ = 20029538016. Its totient is φ = 17804033760.

The previous prime is 18916785847. The next prime is 18916785911. The reversal of 18916785887 is 78858761981.

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

It is a cyclic number.

It is not a de Polignac number, because 18916785887 - 2⁸ = 18916785631 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18916785817) 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, 556376039 + ... + 556376072.

It is an arithmetic number, because the mean of its divisors is an integer number (5007384504).

Almost surely, 2^18916785887 is an apocalyptic number.

18916785887 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

18916785887 is a deficient number, since it is larger than the sum of its proper divisors (1112752129).

18916785887 is a wasteful number, since it uses less digits than its factorization.

18916785887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1112752128.

The product of its digits is 54190080, while the sum is 68.

The spelling of 18916785887 in words is "eighteen billion, nine hundred sixteen million, seven hundred eighty-five thousand, eight hundred eighty-seven".