1271391 has 16 divisors (see below), whose sum is σ = 1883520. Its totient is φ = 756320.

The previous prime is 1271383. The next prime is 1271393. The reversal of 1271391 is 1931721.

It is a cyclic number.

It is not a de Polignac number, because 1271391 - 2³ = 1271383 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1271393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1621 + ... + 2273.

It is an arithmetic number, because the mean of its divisors is an integer number (117720).

2^1271391 is an apocalyptic number.

1271391 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1271391 is a deficient number, since it is larger than the sum of its proper divisors (612129).

1271391 is a wasteful number, since it uses less digits than its factorization.

1271391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 726.

The product of its digits is 378, while the sum is 24.

The square root of 1271391 is about 1127.5597545141. The cubic root of 1271391 is about 108.3327358284.

The spelling of 1271391 in words is "one million, two hundred seventy-one thousand, three hundred ninety-one".