19819966464 has 156 divisors (see below), whose sum is σ = 59374068936. Its totient is φ = 6606323712.

The previous prime is 19819966457. The next prime is 19819966469. The reversal of 19819966464 is 46466991891.

19819966464 is a `hidden beast` number, since 1 + 9 + 81 + 9 + 96 + 6 + 464 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (19819966469) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 985372 + ... + 1005284.

It is an arithmetic number, because the mean of its divisors is an integer number (380603006).

Almost surely, 2^19819966464 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19819966464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29687034468).

19819966464 is an abundant number, since it is smaller than the sum of its proper divisors (39554102472).

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

19819966464 is an frugal number, since it uses more digits than its factorization.

19819966464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19952 (or 19918 counting only the distinct ones).

The product of its digits is 20155392, while the sum is 63.

The spelling of 19819966464 in words is "nineteen billion, eight hundred nineteen million, nine hundred sixty-six thousand, four hundred sixty-four".