717977809495021 has 4 divisors (see below), whose sum is σ = 717991002578044. Its totient is φ = 717964616412000.

The previous prime is 717977809494989. The next prime is 717977809495057. The reversal of 717977809495021 is 120594908779717.

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 651565904072521 + 66411905422500 = 25525789^2 + 8149350^2 .

It is a cyclic number.

It is not a de Polignac number, because 717977809495021 - 2⁵ = 717977809494989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (717977809495421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6596459880 + ... + 6596568721.

It is an arithmetic number, because the mean of its divisors is an integer number (179497750644511).

Almost surely, 2^{717977809495021} is an apocalyptic number.

It is an amenable number.

717977809495021 is a deficient number, since it is larger than the sum of its proper divisors (13193083023).

717977809495021 is a wasteful number, since it uses less digits than its factorization.

717977809495021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13193083022.

The product of its (nonzero) digits is 560105280, while the sum is 76.

The spelling of 717977809495021 in words is "seven hundred seventeen trillion, nine hundred seventy-seven billion, eight hundred nine million, four hundred ninety-five thousand, twenty-one".