19943921604 has 24 divisors (see below), whose sum is σ = 46556627040. Its totient is φ = 6645001024.

The previous prime is 19943921587. The next prime is 19943921617. The reversal of 19943921604 is 40612934991.

It is a happy 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 7 ways as a sum of consecutive naturals, for example, 343569 + ... + 397400.

It is an arithmetic number, because the mean of its divisors is an integer number (1939859460).

Almost surely, 2^19943921604 is an apocalyptic number.

It is an amenable number.

19943921604 is an abundant number, since it is smaller than the sum of its proper divisors (26612705436).

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

19943921604 is a wasteful number, since it uses less digits than its factorization.

19943921604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 743219 (or 743217 counting only the distinct ones).

The product of its (nonzero) digits is 419904, while the sum is 48.

The spelling of 19943921604 in words is "nineteen billion, nine hundred forty-three million, nine hundred twenty-one thousand, six hundred four".