18684399447 has 12 divisors (see below), whose sum is σ = 30844088080. Its totient is φ = 10676799648.

The previous prime is 18684399427. The next prime is 18684399469. The reversal of 18684399447 is 74499348681.

18684399447 is a `hidden beast` number, since 1 + 8 + 68 + 43 + 99 + 447 = 666.

It is not a de Polignac number, because 18684399447 - 2⁸ = 18684399191 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63), and also a Moran number because the ratio is a prime number: 296577769 = 18684399447 / (1 + 8 + 6 + 8 + 4 + 3 + 9 + 9 + 4 + 4 + 7).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18684399427) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 148288822 + ... + 148288947.

Almost surely, 2^18684399447 is an apocalyptic number.

18684399447 is a deficient number, since it is larger than the sum of its proper divisors (12159688633).

18684399447 is a wasteful number, since it uses less digits than its factorization.

18684399447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 296577782 (or 296577779 counting only the distinct ones).

The product of its digits is 41803776, while the sum is 63.

The spelling of 18684399447 in words is "eighteen billion, six hundred eighty-four million, three hundred ninety-nine thousand, four hundred forty-seven".