18987997378 has 8 divisors (see below), whose sum is σ = 32550852672. Its totient is φ = 8137713156.

The previous prime is 18987997373. The next prime is 18987997397. The reversal of 18987997378 is 87379978981.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (18987997373) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 678142750 + ... + 678142777.

It is an arithmetic number, because the mean of its divisors is an integer number (4068856584).

Almost surely, 2^18987997378 is an apocalyptic number.

18987997378 is a deficient number, since it is larger than the sum of its proper divisors (13562855294).

18987997378 is a wasteful number, since it uses less digits than its factorization.

18987997378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1356285536.

The product of its digits is 384072192, while the sum is 76.

The spelling of 18987997378 in words is "eighteen billion, nine hundred eighty-seven million, nine hundred ninety-seven thousand, three hundred seventy-eight".