691983068789 has 4 divisors (see below), whose sum is σ = 698331537420. Its totient is φ = 685634600160.

The previous prime is 691983068753. The next prime is 691983068797. The reversal of 691983068789 is 987860389196.

It is a happy number.

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 521620506289 + 170362562500 = 722233^2 + 412750^2 .

It is a cyclic number.

It is not a de Polignac number, because 691983068789 - 2³² = 687688101493 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 (691983068089) 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, 3174234152 + ... + 3174234369.

It is an arithmetic number, because the mean of its divisors is an integer number (174582884355).

Almost surely, 2^691983068789 is an apocalyptic number.

It is an amenable number.

691983068789 is a deficient number, since it is larger than the sum of its proper divisors (6348468631).

691983068789 is a wasteful number, since it uses less digits than its factorization.

691983068789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6348468630.

The product of its (nonzero) digits is 282175488, while the sum is 74.

The spelling of 691983068789 in words is "six hundred ninety-one billion, nine hundred eighty-three million, sixty-eight thousand, seven hundred eighty-nine".