1387131391 has 2 divisors, whose sum is σ = 1387131392. Its totient is φ = 1387131390.

The previous prime is 1387131373. The next prime is 1387131401. The reversal of 1387131391 is 1931317831.

It is a strong prime.

It is an emirp because it is prime and its reverse (1931317831) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1387131391 - 2⁹ = 1387130879 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1387131391.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1387131191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 693565695 + 693565696.

It is an arithmetic number, because the mean of its divisors is an integer number (693565696).

Almost surely, 2^1387131391 is an apocalyptic number.

1387131391 is a deficient number, since it is larger than the sum of its proper divisors (1).

1387131391 is an equidigital number, since it uses as much as digits as its factorization.

1387131391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13608, while the sum is 37.

The square root of 1387131391 is about 37244.2128524688. The cubic root of 1387131391 is about 1115.2507740286.

The spelling of 1387131391 in words is "one billion, three hundred eighty-seven million, one hundred thirty-one thousand, three hundred ninety-one".