13787 has 4 divisors (see below), whose sum is σ = 14616. Its totient is φ = 12960.

The previous prime is 13781. The next prime is 13789. The reversal of 13787 is 78731.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78731 = 131 ⋅601.

It is a cyclic number.

It is not a de Polignac number, because 13787 - 2⁶ = 13723 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13781) 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, 389 + ... + 422.

It is an arithmetic number, because the mean of its divisors is an integer number (3654).

2¹³⁷⁸⁷ is an apocalyptic number.

13787 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

13787 is a deficient number, since it is larger than the sum of its proper divisors (829).

13787 is an equidigital number, since it uses as much as digits as its factorization.

13787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 828.

The product of its digits is 1176, while the sum is 26.

The square root of 13787 is about 117.4180565331. The cubic root of 13787 is about 23.9785688314.

The spelling of 13787 in words is "thirteen thousand, seven hundred eighty-seven".