19805827968 has 256 divisors, whose sum is σ = 62167694400. Its totient is φ = 6186074112.

The previous prime is 19805827949. The next prime is 19805827973. The reversal of 19805827968 is 86972850891.

It is a happy number.

It is a super-2 number, since 2×19805827968² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16273696 + ... + 16274912.

Almost surely, 2^19805827968 is an apocalyptic number.

19805827968 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 19805827968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31083847200).

19805827968 is an abundant number, since it is smaller than the sum of its proper divisors (42361866432).

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

19805827968 is a wasteful number, since it uses less digits than its factorization.

19805827968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1534 (or 1516 counting only the distinct ones).

The product of its (nonzero) digits is 17418240, while the sum is 63.

The spelling of 19805827968 in words is "nineteen billion, eight hundred five million, eight hundred twenty-seven thousand, nine hundred sixty-eight".