18641978287 has 12 divisors (see below), whose sum is σ = 19239272976. Its totient is φ = 18062559360.

The previous prime is 18641978279. The next prime is 18641978293. The reversal of 18641978287 is 78287914681.

It is not a de Polignac number, because 18641978287 - 2³ = 18641978279 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 (18641978237) 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 11 ways as a sum of consecutive naturals, for example, 301678 + ... + 358180.

It is an arithmetic number, because the mean of its divisors is an integer number (1603272748).

Almost surely, 2^18641978287 is an apocalyptic number.

18641978287 is a deficient number, since it is larger than the sum of its proper divisors (597294689).

18641978287 is an equidigital number, since it uses as much as digits as its factorization.

18641978287 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56818 (or 56781 counting only the distinct ones).

The product of its digits is 10838016, while the sum is 61.

The spelling of 18641978287 in words is "eighteen billion, six hundred forty-one million, nine hundred seventy-eight thousand, two hundred eighty-seven".