12278779 has 4 divisors (see below), whose sum is σ = 12564376. Its totient is φ = 11993184.

The previous prime is 12278767. The next prime is 12278789. The reversal of 12278779 is 97787221.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97787221 = 7 ⋅13969603.

It is a cyclic number.

It is not a de Polignac number, because 12278779 - 2²¹ = 10181627 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43), and also a Moran number because the ratio is a prime number: 285553 = 12278779 / (1 + 2 + 2 + 7 + 8 + 7 + 7 + 9).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12278729) 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, 142734 + ... + 142819.

It is an arithmetic number, because the mean of its divisors is an integer number (3141094).

Almost surely, 2^12278779 is an apocalyptic number.

12278779 is a deficient number, since it is larger than the sum of its proper divisors (285597).

12278779 is an equidigital number, since it uses as much as digits as its factorization.

12278779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285596.

The product of its digits is 98784, while the sum is 43.

The square root of 12278779 is about 3504.1088738793. The cubic root of 12278779 is about 230.7021955234.

The spelling of 12278779 in words is "twelve million, two hundred seventy-eight thousand, seven hundred seventy-nine".