12378778 has 4 divisors (see below), whose sum is σ = 18568170. Its totient is φ = 6189388.

The previous prime is 12378767. The next prime is 12378781. The reversal of 12378778 is 87787321.

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., 12229009 + 149769 = 3497^2 + 387^2 .

It is a plaindrome in base 15.

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, 3094693 + ... + 3094696.

Almost surely, 2^12378778 is an apocalyptic number.

12378778 is a deficient number, since it is larger than the sum of its proper divisors (6189392).

12378778 is an equidigital number, since it uses as much as digits as its factorization.

12378778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6189391.

The product of its digits is 131712, while the sum is 43.

The square root of 12378778 is about 3518.3487604273. The cubic root of 12378778 is about 231.3267864798.

The spelling of 12378778 in words is "twelve million, three hundred seventy-eight thousand, seven hundred seventy-eight".