19871228736 has 504 divisors, whose sum is σ = 66264007680. Its totient is φ = 5657444352.

The previous prime is 19871228711. The next prime is 19871228743. The reversal of 19871228736 is 63782217891.

It is a happy number.

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 71 ways as a sum of consecutive naturals, for example, 156466305 + ... + 156466431.

Almost surely, 2^19871228736 is an apocalyptic number.

19871228736 is a gapful number since it is divisible by the number (16) 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 19871228736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33132003840).

19871228736 is an abundant number, since it is smaller than the sum of its proper divisors (46392778944).

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

19871228736 is a wasteful number, since it uses less digits than its factorization.

19871228736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239 (or 197 counting only the distinct ones).

The product of its digits is 2032128, while the sum is 54.

The spelling of 19871228736 in words is "nineteen billion, eight hundred seventy-one million, two hundred twenty-eight thousand, seven hundred thirty-six".