1396991 has 2 divisors, whose sum is σ = 1396992. Its totient is φ = 1396990.

The previous prime is 1396987. The next prime is 1396999. The reversal of 1396991 is 1996931.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1396991 - 2² = 1396987 is a prime.

It is a zygodrome in base 4.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1396999) 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, 698495 + 698496.

It is an arithmetic number, because the mean of its divisors is an integer number (698496).

2^1396991 is an apocalyptic number.

1396991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1396991 is an equidigital number, since it uses as much as digits as its factorization.

1396991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13122, while the sum is 38.

The square root of 1396991 is about 1181.9437380857. The cubic root of 1396991 is about 111.7886906485.

The spelling of 1396991 in words is "one million, three hundred ninety-six thousand, nine hundred ninety-one".