1099391 has 2 divisors, whose sum is σ = 1099392. Its totient is φ = 1099390.

The previous prime is 1099369. The next prime is 1099393. The reversal of 1099391 is 1939901.

It is a strong prime.

It is an emirp because it is prime and its reverse (1939901) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1099391 - 2⁶ = 1099327 is a prime.

It is a Sophie Germain prime.

Together with 1099393, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1099393) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 549695 + 549696.

It is an arithmetic number, because the mean of its divisors is an integer number (549696).

2^1099391 is an apocalyptic number.

1099391 is a deficient number, since it is larger than the sum of its proper divisors (1).

1099391 is an equidigital number, since it uses as much as digits as its factorization.

1099391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2187, while the sum is 32.

The square root of 1099391 is about 1048.5184786164. The cubic root of 1099391 is about 103.2089577686.

The spelling of 1099391 in words is "one million, ninety-nine thousand, three hundred ninety-one".