19818144864 has 288 divisors, whose sum is σ = 69189120000. Its totient is φ = 5363801856.

The previous prime is 19818144821. The next prime is 19818144889. The reversal of 19818144864 is 46844181891.

19818144864 is a `hidden beast` number, since 1 + 9 + 81 + 81 + 4 + 486 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 19818144864.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1871617 + ... + 1882175.

It is an arithmetic number, because the mean of its divisors is an integer number (240240000).

Almost surely, 2^19818144864 is an apocalyptic number.

19818144864 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19818144864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34594560000).

19818144864 is an abundant number, since it is smaller than the sum of its proper divisors (49370975136).

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

19818144864 is a wasteful number, since it uses less digits than its factorization.

19818144864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10615 (or 10590 counting only the distinct ones).

The product of its digits is 1769472, while the sum is 54.

The spelling of 19818144864 in words is "nineteen billion, eight hundred eighteen million, one hundred forty-four thousand, eight hundred sixty-four".