1278205 has 4 divisors (see below), whose sum is σ = 1533852. Its totient is φ = 1022560.

The previous prime is 1278203. The next prime is 1278209. The reversal of 1278205 is 5028721.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 315844 + 962361 = 562^2 + 981^2 .

It is not a de Polignac number, because 1278205 - 2¹ = 1278203 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1278205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 127816 + ... + 127825.

It is an arithmetic number, because the mean of its divisors is an integer number (383463).

2^1278205 is an apocalyptic number.

It is an amenable number.

1278205 is a deficient number, since it is larger than the sum of its proper divisors (255647).

1278205 is an equidigital number, since it uses as much as digits as its factorization.

1278205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255646.

The product of its (nonzero) digits is 1120, while the sum is 25.

The square root of 1278205 is about 1130.5772861684. The cubic root of 1278205 is about 108.5259269661.

The spelling of 1278205 in words is "one million, two hundred seventy-eight thousand, two hundred five".