18993857278 has 64 divisors (see below), whose sum is σ = 32365884096. Its totient is φ = 8284032000.

The previous prime is 18993857261. The next prime is 18993857279. The reversal of 18993857278 is 87275839981.

It is a super-2 number, since 2×18993857278² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18993857279) 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 31 ways as a sum of consecutive naturals, for example, 20184288 + ... + 20185228.

It is an arithmetic number, because the mean of its divisors is an integer number (505716939).

Almost surely, 2^18993857278 is an apocalyptic number.

18993857278 is a deficient number, since it is larger than the sum of its proper divisors (13372026818).

18993857278 is a wasteful number, since it uses less digits than its factorization.

18993857278 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1309.

The product of its digits is 60963840, while the sum is 67.

The spelling of 18993857278 in words is "eighteen billion, nine hundred ninety-three million, eight hundred fifty-seven thousand, two hundred seventy-eight".