8391491764993 has 4 divisors (see below), whose sum is σ = 8396649413680. Its totient is φ = 8386334116308.

The previous prime is 8391491764969. The next prime is 8391491765003. The reversal of 8391491764993 is 3994671941938.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 8391491764993 - 2⁴¹ = 6192468509441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8391491764793) 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, 2578821903 + ... + 2578825156.

It is an arithmetic number, because the mean of its divisors is an integer number (2099162353420).

Almost surely, 2^{8391491764993} is an apocalyptic number.

It is an amenable number.

8391491764993 is a deficient number, since it is larger than the sum of its proper divisors (5157648687).

8391491764993 is a wasteful number, since it uses less digits than its factorization.

8391491764993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5157648686.

The product of its digits is 317447424, while the sum is 73.

The spelling of 8391491764993 in words is "eight trillion, three hundred ninety-one billion, four hundred ninety-one million, seven hundred sixty-four thousand, nine hundred ninety-three".