12778042 has 4 divisors (see below), whose sum is σ = 19167066. Its totient is φ = 6389020.

The previous prime is 12778037. The next prime is 12778063. The reversal of 12778042 is 24087721.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24087721 = 7 ⋅3441103.

It can be written as a sum of positive squares in only one way, i.e., 11498881 + 1279161 = 3391^2 + 1131^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 12777995 and 12778013.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3194509 + ... + 3194512.

Almost surely, 2^12778042 is an apocalyptic number.

12778042 is a deficient number, since it is larger than the sum of its proper divisors (6389024).

12778042 is an equidigital number, since it uses as much as digits as its factorization.

12778042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6389023.

The product of its (nonzero) digits is 6272, while the sum is 31.

The square root of 12778042 is about 3574.6387230040. The cubic root of 12778042 is about 233.7875808680.

The spelling of 12778042 in words is "twelve million, seven hundred seventy-eight thousand, forty-two".