18647871644 has 12 divisors (see below), whose sum is σ = 34052635344. Its totient is φ = 8918547264.

The previous prime is 18647871629. The next prime is 18647871661. The reversal of 18647871644 is 44617874681.

It is a self number, because there is not a number n which added to its sum of digits gives 18647871644.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 101347037 + ... + 101347220.

It is an arithmetic number, because the mean of its divisors is an integer number (2837719612).

Almost surely, 2^18647871644 is an apocalyptic number.

It is an amenable number.

18647871644 is a deficient number, since it is larger than the sum of its proper divisors (15404763700).

18647871644 is a wasteful number, since it uses less digits than its factorization.

18647871644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202694284 (or 202694282 counting only the distinct ones).

The product of its digits is 7225344, while the sum is 56.

The spelling of 18647871644 in words is "eighteen billion, six hundred forty-seven million, eight hundred seventy-one thousand, six hundred forty-four".