12278645 has 4 divisors (see below), whose sum is σ = 14734380. Its totient is φ = 9822912.

The previous prime is 12278633. The next prime is 12278647. The reversal of 12278645 is 54687221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54687221 = 37 ⋅1478033.

It can be written as a sum of positive squares in 2 ways, for example, as 4831204 + 7447441 = 2198^2 + 2729^2 .

It is a cyclic number.

It is not a de Polignac number, because 12278645 - 2¹⁶ = 12213109 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12278647) 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, 1227860 + ... + 1227869.

It is an arithmetic number, because the mean of its divisors is an integer number (3683595).

Almost surely, 2^12278645 is an apocalyptic number.

It is an amenable number.

12278645 is a deficient number, since it is larger than the sum of its proper divisors (2455735).

12278645 is an equidigital number, since it uses as much as digits as its factorization.

12278645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2455734.

The product of its digits is 26880, while the sum is 35.

The square root of 12278645 is about 3504.0897534167. The cubic root of 12278645 is about 230.7013562921.

The spelling of 12278645 in words is "twelve million, two hundred seventy-eight thousand, six hundred forty-five".