1690691 has 2 divisors, whose sum is σ = 1690692. Its totient is φ = 1690690.

The previous prime is 1690687. The next prime is 1690693. The reversal of 1690691 is 1960961.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (1960961) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1690691 - 2² = 1690687 is a prime.

Together with 1690693, it forms a pair of twin primes.

It is a Chen prime.

1690691 is a strobogrammatic number because it is the same when read upside-down.

It is not a weakly prime, because it can be changed into another prime (1690693) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 845345 + 845346.

It is an arithmetic number, because the mean of its divisors is an integer number (845346).

2^1690691 is an apocalyptic number.

1690691 is a deficient number, since it is larger than the sum of its proper divisors (1).

1690691 is an equidigital number, since it uses as much as digits as its factorization.

1690691 is an evil number, because the sum of its binary digits is even.

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

The square root of 1690691 is about 1300.2657420697. The cubic root of 1690691 is about 119.1300745610.

The spelling of 1690691 in words is "one million, six hundred ninety thousand, six hundred ninety-one".