19867978368 has 768 divisors, whose sum is σ = 73322496000. Its totient is φ = 5036359680.

The previous prime is 19867978331. The next prime is 19867978369. The reversal of 19867978368 is 86387976891.

19867978368 is a `hidden beast` number, since 198 + 6 + 7 + 9 + 78 + 368 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

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

It is a junction number, because it is equal to n+sod(n) for n = 19867978296 and 19867978305.

It is not an unprimeable number, because it can be changed into a prime (19867978369) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 223235668 + ... + 223235756.

It is an arithmetic number, because the mean of its divisors is an integer number (95472000).

Almost surely, 2^19867978368 is an apocalyptic number.

19867978368 is a gapful number since it is divisible by the number (18) 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 19867978368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36661248000).

19867978368 is an abundant number, since it is smaller than the sum of its proper divisors (53454517632).

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

19867978368 is a wasteful number, since it uses less digits than its factorization.

19867978368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213 (or 198 counting only the distinct ones).

The product of its digits is 219469824, while the sum is 72.

The spelling of 19867978368 in words is "nineteen billion, eight hundred sixty-seven million, nine hundred seventy-eight thousand, three hundred sixty-eight".