691319440613 has 4 divisors (see below), whose sum is σ = 692227876908. Its totient is φ = 690411004320.

The previous prime is 691319440597. The next prime is 691319440631. The reversal of 691319440613 is 316044913196.

691319440613 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 125066200609 + 566253240004 = 353647^2 + 752498^2 .

It is a cyclic number.

It is not a de Polignac number, because 691319440613 - 2⁴ = 691319440597 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 (691319440213) 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, 454217006 + ... + 454218527.

It is an arithmetic number, because the mean of its divisors is an integer number (173056969227).

Almost surely, 2^691319440613 is an apocalyptic number.

It is an amenable number.

691319440613 is a deficient number, since it is larger than the sum of its proper divisors (908436295).

691319440613 is an equidigital number, since it uses as much as digits as its factorization.

691319440613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 908436294.

The product of its (nonzero) digits is 419904, while the sum is 47.

The spelling of 691319440613 in words is "six hundred ninety-one billion, three hundred nineteen million, four hundred forty thousand, six hundred thirteen".