1278491 has 4 divisors (see below), whose sum is σ = 1345800. Its totient is φ = 1211184.

The previous prime is 1278481. The next prime is 1278493. The reversal of 1278491 is 1948721.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1278491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1278493) 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, 33626 + ... + 33663.

It is an arithmetic number, because the mean of its divisors is an integer number (336450).

2^1278491 is an apocalyptic number.

1278491 is a deficient number, since it is larger than the sum of its proper divisors (67309).

1278491 is an equidigital number, since it uses as much as digits as its factorization.

1278491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67308.

The product of its digits is 4032, while the sum is 32.

The square root of 1278491 is about 1130.7037631493. The cubic root of 1278491 is about 108.5340206340.

The spelling of 1278491 in words is "one million, two hundred seventy-eight thousand, four hundred ninety-one".