19713433921 has 8 divisors (see below), whose sum is σ = 19858551944. Its totient is φ = 19568839680.

The previous prime is 19713433879. The next prime is 19713433931. The reversal of 19713433921 is 12933431791.

It can be written as a sum of positive squares in 4 ways, for example, as 102232321 + 19611201600 = 10111^2 + 140040^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 19713433921 - 2¹¹ = 19713431873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19713433931) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55236 + ... + 206101.

It is an arithmetic number, because the mean of its divisors is an integer number (2482318993).

Almost surely, 2^19713433921 is an apocalyptic number.

It is an amenable number.

19713433921 is a deficient number, since it is larger than the sum of its proper divisors (145118023).

19713433921 is a wasteful number, since it uses less digits than its factorization.

19713433921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 261891.

The product of its digits is 122472, while the sum is 43.

The spelling of 19713433921 in words is "nineteen billion, seven hundred thirteen million, four hundred thirty-three thousand, nine hundred twenty-one".