18872136644 has 12 divisors (see below), whose sum is σ = 33236598444. Its totient is φ = 9375965664.

The previous prime is 18872136641. The next prime is 18872136659. The reversal of 18872136644 is 44663127881.

It can be written as a sum of positive squares in 2 ways, for example, as 7041223744 + 11830912900 = 83912^2 + 108770^2 .

It is a junction number, because it is equal to n+sod(n) for n = 18872136592 and 18872136601.

It is not an unprimeable number, because it can be changed into a prime (18872136641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15024959 + ... + 15026214.

It is an arithmetic number, because the mean of its divisors is an integer number (2769716537).

Almost surely, 2^18872136644 is an apocalyptic number.

It is an amenable number.

18872136644 is a deficient number, since it is larger than the sum of its proper divisors (14364461800).

18872136644 is a wasteful number, since it uses less digits than its factorization.

18872136644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30051334 (or 30051332 counting only the distinct ones).

The product of its digits is 1548288, while the sum is 50.

The spelling of 18872136644 in words is "eighteen billion, eight hundred seventy-two million, one hundred thirty-six thousand, six hundred forty-four".