1386991 has 2 divisors, whose sum is σ = 1386992. Its totient is φ = 1386990.

The previous prime is 1386977. The next prime is 1387007. The reversal of 1386991 is 1996831.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1386991 - 2⁷ = 1386863 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1386991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1386901) 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 as a sum of consecutive naturals, namely, 693495 + 693496.

It is an arithmetic number, because the mean of its divisors is an integer number (693496).

2^1386991 is an apocalyptic number.

1386991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1386991 is an equidigital number, since it uses as much as digits as its factorization.

1386991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11664, while the sum is 37.

The square root of 1386991 is about 1177.7058206530. The cubic root of 1386991 is about 111.5213148068.

The spelling of 1386991 in words is "one million, three hundred eighty-six thousand, nine hundred ninety-one".