1691087 has 2 divisors, whose sum is σ = 1691088. Its totient is φ = 1691086.

The previous prime is 1691069. The next prime is 1691093. The reversal of 1691087 is 7801961.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1691087 - 2⁶ = 1691023 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1691387) 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, 845543 + 845544.

It is an arithmetic number, because the mean of its divisors is an integer number (845544).

2^1691087 is an apocalyptic number.

1691087 is a deficient number, since it is larger than the sum of its proper divisors (1).

1691087 is an equidigital number, since it uses as much as digits as its factorization.

1691087 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3024, while the sum is 32.

The square root of 1691087 is about 1300.4180097184. The cubic root of 1691087 is about 119.1393748662.

The spelling of 1691087 in words is "one million, six hundred ninety-one thousand, eighty-seven".