13781017 has 4 divisors (see below), whose sum is σ = 13789620. Its totient is φ = 13772416.

The previous prime is 13780993. The next prime is 13781039. The reversal of 13781017 is 71018731.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 2996361 + 10784656 = 1731^2 + 3284^2 .

It is a cyclic number.

It is not a de Polignac number, because 13781017 - 2¹⁵ = 13748249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13781087) 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, 1108 + ... + 5365.

It is an arithmetic number, because the mean of its divisors is an integer number (3447405).

Almost surely, 2^13781017 is an apocalyptic number.

It is an amenable number.

13781017 is a deficient number, since it is larger than the sum of its proper divisors (8603).

13781017 is an equidigital number, since it uses as much as digits as its factorization.

13781017 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8602.

The product of its (nonzero) digits is 1176, while the sum is 28.

The square root of 13781017 is about 3712.2792190243. The cubic root of 13781017 is about 239.7509975338.

Adding to 13781017 its reverse (71018731), we get a palindrome (84799748).

The spelling of 13781017 in words is "thirteen million, seven hundred eighty-one thousand, seventeen".