18865963818 has 144 divisors (see below), whose sum is σ = 46933825536. Its totient is φ = 5464817280.

The previous prime is 18865963817. The next prime is 18865963903. The reversal of 18865963818 is 81836956881.

18865963818 is a `hidden beast` number, since 1 + 8 + 8 + 6 + 596 + 38 + 1 + 8 = 666.

It is not an unprimeable number, because it can be changed into a prime (18865963811) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 3486471 + ... + 3491877.

It is an arithmetic number, because the mean of its divisors is an integer number (325929344).

Almost surely, 2^18865963818 is an apocalyptic number.

18865963818 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18865963818, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23466912768).

18865963818 is an abundant number, since it is smaller than the sum of its proper divisors (28067861718).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18865963818 is a wasteful number, since it uses less digits than its factorization.

18865963818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5509 (or 5493 counting only the distinct ones).

The product of its digits is 19906560, while the sum is 63.

The spelling of 18865963818 in words is "eighteen billion, eight hundred sixty-five million, nine hundred sixty-three thousand, eight hundred eighteen".