691116959117 has 4 divisors (see below), whose sum is σ = 744279802140. Its totient is φ = 637954116096.

The previous prime is 691116959111. The next prime is 691116959131. The reversal of 691116959117 is 711959611196.

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 122677864516 + 568439094601 = 350254^2 + 753949^2 .

It is a cyclic number.

It is not a de Polignac number, because 691116959117 - 2⁶ = 691116959053 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 (691116959111) 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, 26581421492 + ... + 26581421517.

It is an arithmetic number, because the mean of its divisors is an integer number (186069950535).

Almost surely, 2^691116959117 is an apocalyptic number.

It is an amenable number.

691116959117 is a deficient number, since it is larger than the sum of its proper divisors (53162843023).

691116959117 is a wasteful number, since it uses less digits than its factorization.

691116959117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53162843022.

The product of its digits is 918540, while the sum is 56.

The spelling of 691116959117 in words is "six hundred ninety-one billion, one hundred sixteen million, nine hundred fifty-nine thousand, one hundred seventeen".