19991220480 has 864 divisors, whose sum is σ = 89139068928. Its totient is φ = 4014489600.

The previous prime is 19991220439. The next prime is 19991220493. The reversal of 19991220480 is 8402219991.

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

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 95 ways as a sum of consecutive naturals, for example, 27497877 + ... + 27498603.

Almost surely, 2^19991220480 is an apocalyptic number.

19991220480 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 19991220480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44569534464).

19991220480 is an abundant number, since it is smaller than the sum of its proper divisors (69147848448).

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

19991220480 is a wasteful number, since it uses less digits than its factorization.

19991220480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 803 (or 786 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

It can be divided in two parts, 19991 and 220480, that added together give a triangular number (240471 = T₆₉₃).

The spelling of 19991220480 in words is "nineteen billion, nine hundred ninety-one million, two hundred twenty thousand, four hundred eighty".