12778 has 4 divisors (see below), whose sum is σ = 19170. Its totient is φ = 6388.

The previous prime is 12763. The next prime is 12781. The reversal of 12778 is 87721.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 12769 + 9 = 113^2 + 3^2 .

It is a plaindrome in base 10 and base 15.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3193 + ... + 3196.

2¹²⁷⁷⁸ is an apocalyptic number.

12778 is a deficient number, since it is larger than the sum of its proper divisors (6392).

12778 is an equidigital number, since it uses as much as digits as its factorization.

12778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6391.

The product of its digits is 784, while the sum is 25.

The square root of 12778 is about 113.0398159942. The cubic root of 12778 is about 23.3787324723.

The spelling of 12778 in words is "twelve thousand, seven hundred seventy-eight".