13813336781 has 4 divisors (see below), whose sum is σ = 13813572864. Its totient is φ = 13813100700.

The previous prime is 13813336777. The next prime is 13813336787. The reversal of 13813336781 is 18763331831.

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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 13813336781 - 2² = 13813336777 is a prime.

It is a super-2 number, since 2×13813336781² (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 (13813336787) 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, 42566 + ... + 171576.

It is an arithmetic number, because the mean of its divisors is an integer number (3453393216).

Almost surely, 2^13813336781 is an apocalyptic number.

It is an amenable number.

13813336781 is a deficient number, since it is larger than the sum of its proper divisors (236083).

13813336781 is a wasteful number, since it uses less digits than its factorization.

13813336781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236082.

The product of its digits is 217728, while the sum is 44.

The spelling of 13813336781 in words is "thirteen billion, eight hundred thirteen million, three hundred thirty-six thousand, seven hundred eighty-one".