19836644380 has 96 divisors (see below), whose sum is σ = 49392685440. Its totient is φ = 6547537920.

The previous prime is 19836644371. The next prime is 19836644381. The reversal of 19836644380 is 8344663891.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19836644381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1426260 + ... + 1440100.

It is an arithmetic number, because the mean of its divisors is an integer number (514507140).

Almost surely, 2^19836644380 is an apocalyptic number.

19836644380 is a gapful number since it is divisible by the number (10) 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 19836644380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24696342720).

19836644380 is an abundant number, since it is smaller than the sum of its proper divisors (29556041060).

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

19836644380 is a wasteful number, since it uses less digits than its factorization.

19836644380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14239 (or 14237 counting only the distinct ones).

The product of its (nonzero) digits is 2985984, while the sum is 52.

The spelling of 19836644380 in words is "nineteen billion, eight hundred thirty-six million, six hundred forty-four thousand, three hundred eighty".