13691593781 has 4 divisors (see below), whose sum is σ = 14412204000. Its totient is φ = 12970983564.

The previous prime is 13691593693. The next prime is 13691593843. The reversal of 13691593781 is 18739519631.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18739519631 = 7 ⋅2677074233.

It is a cyclic number.

It is not a de Polignac number, because 13691593781 - 2¹⁸ = 13691331637 is a prime.

It is a super-2 number, since 2×13691593781² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13691593081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 360305081 + ... + 360305118.

It is an arithmetic number, because the mean of its divisors is an integer number (3603051000).

Almost surely, 2^13691593781 is an apocalyptic number.

It is an amenable number.

13691593781 is a deficient number, since it is larger than the sum of its proper divisors (720610219).

13691593781 is an equidigital number, since it uses as much as digits as its factorization.

13691593781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 720610218.

The product of its digits is 1224720, while the sum is 53.

The spelling of 13691593781 in words is "thirteen billion, six hundred ninety-one million, five hundred ninety-three thousand, seven hundred eighty-one".