691088288041 has 4 divisors (see below), whose sum is σ = 691090201300. Its totient is φ = 691086374784.

The previous prime is 691088288039. The next prime is 691088288071. The reversal of 691088288041 is 140882880196.

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 18393055641 + 672695232400 = 135621^2 + 820180^2 .

It is a cyclic number.

It is not a de Polignac number, because 691088288041 - 2¹ = 691088288039 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (691088288021) 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, 231696 + ... + 1198273.

It is an arithmetic number, because the mean of its divisors is an integer number (172772550325).

Almost surely, 2^691088288041 is an apocalyptic number.

It is an amenable number.

691088288041 is a deficient number, since it is larger than the sum of its proper divisors (1913259).

691088288041 is a wasteful number, since it uses less digits than its factorization.

691088288041 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1913258.

The product of its (nonzero) digits is 1769472, while the sum is 55.

The spelling of 691088288041 in words is "six hundred ninety-one billion, eighty-eight million, two hundred eighty-eight thousand, forty-one".