19721079072 has 72 divisors (see below), whose sum is σ = 58158945936. Its totient is φ = 6573690432.

The previous prime is 19721079031. The next prime is 19721079073. The reversal of 19721079072 is 27097012791.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (72).

It is not an unprimeable number, because it can be changed into a prime (19721079073) 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 11 ways as a sum of consecutive naturals, for example, 1260298 + ... + 1275849.

It is an arithmetic number, because the mean of its divisors is an integer number (807763138).

Almost surely, 2^19721079072 is an apocalyptic number.

19721079072 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

19721079072 is an abundant number, since it is smaller than the sum of its proper divisors (38437866864).

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

19721079072 is an equidigital number, since it uses as much as digits as its factorization.

19721079072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2536172 (or 2536152 counting only the distinct ones).

The product of its (nonzero) digits is 111132, while the sum is 45.

The spelling of 19721079072 in words is "nineteen billion, seven hundred twenty-one million, seventy-nine thousand, seventy-two".