13668781 has 8 divisors (see below), whose sum is σ = 15691520. Its totient is φ = 11663568.

The previous prime is 13668779. The next prime is 13668793. The reversal of 13668781 is 18786631.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 13668781 - 2¹ = 13668779 is a prime.

It is a super-2 number, since 2×13668781² = 373671148051922, which contains 22 as substring.

It is a Duffinian number.

It is a zygodrome in base 5.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13668701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2661 + ... + 5866.

It is an arithmetic number, because the mean of its divisors is an integer number (1961440).

Almost surely, 2^13668781 is an apocalyptic number.

It is an amenable number.

13668781 is a deficient number, since it is larger than the sum of its proper divisors (2022739).

13668781 is an equidigital number, since it uses as much as digits as its factorization.

13668781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8763.

The product of its digits is 48384, while the sum is 40.

The square root of 13668781 is about 3697.1314556018. The cubic root of 13668781 is about 239.0983588199.

The spelling of 13668781 in words is "thirteen million, six hundred sixty-eight thousand, seven hundred eighty-one".