18378691547 has 4 divisors (see below), whose sum is σ = 18380514360. Its totient is φ = 18376868736.

The previous prime is 18378691531. The next prime is 18378691561. The reversal of 18378691547 is 74519687381.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74519687381 = 262433 ⋅283957.

It is a cyclic number.

It is not a de Polignac number, because 18378691547 - 2⁴ = 18378691531 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18378681547) 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, 896198 + ... + 916475.

It is an arithmetic number, because the mean of its divisors is an integer number (4595128590).

Almost surely, 2^18378691547 is an apocalyptic number.

18378691547 is a deficient number, since it is larger than the sum of its proper divisors (1822813).

18378691547 is a wasteful number, since it uses less digits than its factorization.

18378691547 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1822812.

The product of its digits is 10160640, while the sum is 59.

The spelling of 18378691547 in words is "eighteen billion, three hundred seventy-eight million, six hundred ninety-one thousand, five hundred forty-seven".