19721306880 has 432 divisors, whose sum is σ = 78364016640. Its totient is φ = 4528742400.

The previous prime is 19721306873. The next prime is 19721306953. The reversal of 19721306880 is 8860312791.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2403585 + ... + 2411775.

Almost surely, 2^19721306880 is an apocalyptic number.

19721306880 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 19721306880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39182008320).

19721306880 is an abundant number, since it is smaller than the sum of its proper divisors (58642709760).

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

19721306880 is a wasteful number, since it uses less digits than its factorization.

19721306880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8248 (or 8231 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The spelling of 19721306880 in words is "nineteen billion, seven hundred twenty-one million, three hundred six thousand, eight hundred eighty".