18887188717 has 4 divisors (see below), whose sum is σ = 19998199836. Its totient is φ = 17776177600.

The previous prime is 18887188711. The next prime is 18887188739. The reversal of 18887188717 is 71788178881.

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 10935721476 + 7951467241 = 104574^2 + 89171^2 .

It is a cyclic number.

It is not a de Polignac number, because 18887188717 - 2³¹ = 16739705069 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 (18887188711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 555505534 + ... + 555505567.

It is an arithmetic number, because the mean of its divisors is an integer number (4999549959).

Almost surely, 2^18887188717 is an apocalyptic number.

18887188717 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

18887188717 is a deficient number, since it is larger than the sum of its proper divisors (1111011119).

18887188717 is a wasteful number, since it uses less digits than its factorization.

18887188717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1111011118.

The product of its digits is 11239424, while the sum is 64.

The spelling of 18887188717 in words is "eighteen billion, eight hundred eighty-seven million, one hundred eighty-eight thousand, seven hundred seventeen".