1276391 has 4 divisors (see below), whose sum is σ = 1278984. Its totient is φ = 1273800.

The previous prime is 1276361. The next prime is 1276397. The reversal of 1276391 is 1936721.

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-1276391 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1276397) 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, 305 + ... + 1626.

It is an arithmetic number, because the mean of its divisors is an integer number (319746).

2^1276391 is an apocalyptic number.

1276391 is a deficient number, since it is larger than the sum of its proper divisors (2593).

1276391 is an equidigital number, since it uses as much as digits as its factorization.

1276391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2592.

The product of its digits is 2268, while the sum is 29.

The square root of 1276391 is about 1129.7747563121. The cubic root of 1276391 is about 108.4745634695.

The spelling of 1276391 in words is "one million, two hundred seventy-six thousand, three hundred ninety-one".