1278861 has 4 divisors (see below), whose sum is σ = 1705152. Its totient is φ = 852572.

The previous prime is 1278857. The next prime is 1278881. The reversal of 1278861 is 1688721.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1278861 - 2² = 1278857 is a prime.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278811) 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, 213141 + ... + 213146.

It is an arithmetic number, because the mean of its divisors is an integer number (426288).

2^1278861 is an apocalyptic number.

It is an amenable number.

1278861 is a deficient number, since it is larger than the sum of its proper divisors (426291).

1278861 is an equidigital number, since it uses as much as digits as its factorization.

1278861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 426290.

The product of its digits is 5376, while the sum is 33.

The square root of 1278861 is about 1130.8673662282. The cubic root of 1278861 is about 108.5444896725.

The spelling of 1278861 in words is "one million, two hundred seventy-eight thousand, eight hundred sixty-one".