18378789128399 has 32 divisors (see below), whose sum is σ = 22698933264000. Its totient is φ = 14823202652160.

The previous prime is 18378789128383. The next prime is 18378789128471. The reversal of 18378789128399 is 99382198787381.

It is not a de Polignac number, because 18378789128399 - 2⁴ = 18378789128383 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18378789128369) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 25351439 + ... + 26066319.

It is an arithmetic number, because the mean of its divisors is an integer number (709341664500).

Almost surely, 2^{18378789128399} is an apocalyptic number.

18378789128399 is a deficient number, since it is larger than the sum of its proper divisors (4320144135601).

18378789128399 is an equidigital number, since it uses as much as digits as its factorization.

18378789128399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 719328 (or 719314 counting only the distinct ones).

The product of its digits is 2633637888, while the sum is 83.

The spelling of 18378789128399 in words is "eighteen trillion, three hundred seventy-eight billion, seven hundred eighty-nine million, one hundred twenty-eight thousand, three hundred ninety-nine".