12715778 has 4 divisors (see below), whose sum is σ = 19073670. Its totient is φ = 6357888.

The previous prime is 12715771. The next prime is 12715783. The reversal of 12715778 is 87751721.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87751721 = 1009 ⋅86969.

It can be written as a sum of positive squares in only one way, i.e., 11377129 + 1338649 = 3373^2 + 1157^2 .

It is not an unprimeable number, because it can be changed into a prime (12715771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3178943 + ... + 3178946.

Almost surely, 2^12715778 is an apocalyptic number.

12715778 is a deficient number, since it is larger than the sum of its proper divisors (6357892).

12715778 is an equidigital number, since it uses as much as digits as its factorization.

12715778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6357891.

The product of its digits is 27440, while the sum is 38.

The square root of 12715778 is about 3565.9189558934. The cubic root of 12715778 is about 233.4072341882.

The spelling of 12715778 in words is "twelve million, seven hundred fifteen thousand, seven hundred seventy-eight".