691104321943 has 4 divisors (see below), whose sum is σ = 789833510800. Its totient is φ = 592375133088.

The previous prime is 691104321883. The next prime is 691104321967. The reversal of 691104321943 is 349123401196.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 691104321943 - 2¹⁷ = 691104190871 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 691104321943.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691104321983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49364594418 + ... + 49364594431.

It is an arithmetic number, because the mean of its divisors is an integer number (197458377700).

Almost surely, 2^691104321943 is an apocalyptic number.

691104321943 is a deficient number, since it is larger than the sum of its proper divisors (98729188857).

691104321943 is an equidigital number, since it uses as much as digits as its factorization.

691104321943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98729188856.

The product of its (nonzero) digits is 139968, while the sum is 43.

The spelling of 691104321943 in words is "six hundred ninety-one billion, one hundred four million, three hundred twenty-one thousand, nine hundred forty-three".