1691099 has 2 divisors, whose sum is σ = 1691100. Its totient is φ = 1691098.

The previous prime is 1691093. The next prime is 1691101. The reversal of 1691099 is 9901961.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1691099 is a prime.

It is a Sophie Germain prime.

Together with 1691101, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1691093) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 845549 + 845550.

It is an arithmetic number, because the mean of its divisors is an integer number (845550).

2^1691099 is an apocalyptic number.

1691099 is a deficient number, since it is larger than the sum of its proper divisors (1).

1691099 is an equidigital number, since it uses as much as digits as its factorization.

1691099 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4374, while the sum is 35.

The square root of 1691099 is about 1300.4226236113. The cubic root of 1691099 is about 119.1396566710.

The spelling of 1691099 in words is "one million, six hundred ninety-one thousand, ninety-nine".