19721304118 has 4 divisors (see below), whose sum is σ = 29581956180. Its totient is φ = 9860652058.

The previous prime is 19721304089. The next prime is 19721304133. The reversal of 19721304118 is 81140312791.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×19721304118² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4930326028 + ... + 4930326031.

It is an arithmetic number, because the mean of its divisors is an integer number (7395489045).

Almost surely, 2^19721304118 is an apocalyptic number.

19721304118 is a deficient number, since it is larger than the sum of its proper divisors (9860652062).

19721304118 is an equidigital number, since it uses as much as digits as its factorization.

19721304118 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9860652061.

The product of its (nonzero) digits is 12096, while the sum is 37.

The spelling of 19721304118 in words is "nineteen billion, seven hundred twenty-one million, three hundred four thousand, one hundred eighteen".