1397271391 has 2 divisors, whose sum is σ = 1397271392. Its totient is φ = 1397271390.

The previous prime is 1397271389. The next prime is 1397271433. The reversal of 1397271391 is 1931727931.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1397271391 - 2¹ = 1397271389 is a prime.

Together with 1397271389, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1397271331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 698635695 + 698635696.

It is an arithmetic number, because the mean of its divisors is an integer number (698635696).

Almost surely, 2^1397271391 is an apocalyptic number.

1397271391 is a deficient number, since it is larger than the sum of its proper divisors (1).

1397271391 is an equidigital number, since it uses as much as digits as its factorization.

1397271391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 71442, while the sum is 43.

The square root of 1397271391 is about 37380.0935124566. The cubic root of 1397271391 is about 1117.9616920917.

The spelling of 1397271391 in words is "one billion, three hundred ninety-seven million, two hundred seventy-one thousand, three hundred ninety-one".