1609691 has 2 divisors, whose sum is σ = 1609692. Its totient is φ = 1609690.

The previous prime is 1609669. The next prime is 1609693. The reversal of 1609691 is 1969061.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1609691 - 2⁶ = 1609627 is a prime.

It is a super-3 number, since 3×1609691³ = 12512635753331179113, which contains 333 as substring. Note that it is a super-d number also for d = 2.

Together with 1609693, 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 (1609693) 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, 804845 + 804846.

It is an arithmetic number, because the mean of its divisors is an integer number (804846).

2^1609691 is an apocalyptic number.

1609691 is a deficient number, since it is larger than the sum of its proper divisors (1).

1609691 is an equidigital number, since it uses as much as digits as its factorization.

1609691 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2916, while the sum is 32.

The square root of 1609691 is about 1268.7359851443. The cubic root of 1609691 is about 117.1963731711.

The spelling of 1609691 in words is "one million, six hundred nine thousand, six hundred ninety-one".