19931386809601 has 4 divisors (see below), whose sum is σ = 20032561362132. Its totient is φ = 19830212257072.

The previous prime is 19931386809583. The next prime is 19931386809611. The reversal of 19931386809601 is 10690868313991.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 15016586015376 + 4914800794225 = 3875124^2 + 2216935^2 .

It is a cyclic number.

It is not a de Polignac number, because 19931386809601 - 2¹⁷ = 19931386678529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19931386809611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50587275970 + ... + 50587276363.

It is an arithmetic number, because the mean of its divisors is an integer number (5008140340533).

Almost surely, 2^{19931386809601} is an apocalyptic number.

It is an amenable number.

19931386809601 is a deficient number, since it is larger than the sum of its proper divisors (101174552531).

19931386809601 is a wasteful number, since it uses less digits than its factorization.

19931386809601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101174552530.

The product of its (nonzero) digits is 15116544, while the sum is 64.

The spelling of 19931386809601 in words is "nineteen trillion, nine hundred thirty-one billion, three hundred eighty-six million, eight hundred nine thousand, six hundred one".