1279391 has 4 divisors (see below), whose sum is σ = 1284384. Its totient is φ = 1274400.

The previous prime is 1279361. The next prime is 1279417. The reversal of 1279391 is 1939721.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 1279391 - 2¹⁴ = 1263007 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 (1279321) 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, 2090 + ... + 2631.

It is an arithmetic number, because the mean of its divisors is an integer number (321096).

2^1279391 is an apocalyptic number.

1279391 is a deficient number, since it is larger than the sum of its proper divisors (4993).

1279391 is an equidigital number, since it uses as much as digits as its factorization.

1279391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4992.

The product of its digits is 3402, while the sum is 32.

The square root of 1279391 is about 1131.1016753590. The cubic root of 1279391 is about 108.5594823454.

The spelling of 1279391 in words is "one million, two hundred seventy-nine thousand, three hundred ninety-one".