79721308684993 has 4 divisors (see below), whose sum is σ = 80024431531968. Its totient is φ = 79418185838020.

The previous prime is 79721308684981. The next prime is 79721308685023. The reversal of 79721308684993 is 39948680312797.

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 a de Polignac number, because none of the positive numbers 2^k-79721308684993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (79721308684093) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 151561423093 + ... + 151561423618.

It is an arithmetic number, because the mean of its divisors is an integer number (20006107882992).

Almost surely, 2^{79721308684993} is an apocalyptic number.

It is an amenable number.

79721308684993 is a deficient number, since it is larger than the sum of its proper divisors (303122846975).

79721308684993 is a wasteful number, since it uses less digits than its factorization.

79721308684993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 303122846974.

The product of its (nonzero) digits is 987614208, while the sum is 76.

The spelling of 79721308684993 in words is "seventy-nine trillion, seven hundred twenty-one billion, three hundred eight million, six hundred eighty-four thousand, nine hundred ninety-three".