19891317983 has 4 divisors (see below), whose sum is σ = 19916276520. Its totient is φ = 19866359448.

The previous prime is 19891317967. The next prime is 19891318003. The reversal of 19891317983 is 38971319891.

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

It is a cyclic number.

It is not a de Polignac number, because 19891317983 - 2⁴ = 19891317967 is a prime.

It is a super-3 number, since 3×19891317983³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19891317913) 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, 12478073 + ... + 12479666.

It is an arithmetic number, because the mean of its divisors is an integer number (4979069130).

Almost surely, 2^19891317983 is an apocalyptic number.

19891317983 is a deficient number, since it is larger than the sum of its proper divisors (24958537).

19891317983 is an equidigital number, since it uses as much as digits as its factorization.

19891317983 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24958536.

The product of its digits is 2939328, while the sum is 59.

The spelling of 19891317983 in words is "nineteen billion, eight hundred ninety-one million, three hundred seventeen thousand, nine hundred eighty-three".