18378789128402 has 4 divisors (see below), whose sum is σ = 27568183692606. Its totient is φ = 9189394564200.

The previous prime is 18378789128383. The next prime is 18378789128471. The reversal of 18378789128402 is 20482198787381.

It is a Cunningham number, because it is equal to 4287049²+1.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 18378789128401 + 1 = 4287049^2 + 1^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 4594697282099 + ... + 4594697282102.

Almost surely, 2^{18378789128402} is an apocalyptic number.

18378789128402 is a deficient number, since it is larger than the sum of its proper divisors (9189394564204).

18378789128402 is an equidigital number, since it uses as much as digits as its factorization.

18378789128402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9189394564203.

The product of its (nonzero) digits is 86704128, while the sum is 68.

The spelling of 18378789128402 in words is "eighteen trillion, three hundred seventy-eight billion, seven hundred eighty-nine million, one hundred twenty-eight thousand, four hundred two".