13781387 has 4 divisors (see below), whose sum is σ = 14074656. Its totient is φ = 13488120.

The previous prime is 13781381. The next prime is 13781399. The reversal of 13781387 is 78318731.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78318731 = 877 ⋅89303.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13781387 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 13781387.

It is not an unprimeable number, because it can be changed into a prime (13781381) 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 3 ways as a sum of consecutive naturals, for example, 146564 + ... + 146657.

It is an arithmetic number, because the mean of its divisors is an integer number (3518664).

Almost surely, 2^13781387 is an apocalyptic number.

13781387 is a deficient number, since it is larger than the sum of its proper divisors (293269).

13781387 is an equidigital number, since it uses as much as digits as its factorization.

13781387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 293268.

The product of its digits is 28224, while the sum is 38.

The square root of 13781387 is about 3712.3290533033. The cubic root of 13781387 is about 239.7531431682.

The spelling of 13781387 in words is "thirteen million, seven hundred eighty-one thousand, three hundred eighty-seven".