1693661 has 2 divisors, whose sum is σ = 1693662. Its totient is φ = 1693660.

The previous prime is 1693649. The next prime is 1693663. The reversal of 1693661 is 1663961.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1651225 + 42436 = 1285^2 + 206^2 .

It is a cyclic number.

It is not a de Polignac number, because 1693661 - 2¹⁰ = 1692637 is a prime.

It is a Sophie Germain prime.

Together with 1693663, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1693663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 846830 + 846831.

It is an arithmetic number, because the mean of its divisors is an integer number (846831).

2^1693661 is an apocalyptic number.

It is an amenable number.

1693661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1693661 is an equidigital number, since it uses as much as digits as its factorization.

1693661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5832, while the sum is 32.

The square root of 1693661 is about 1301.4073151785. The cubic root of 1693661 is about 119.1997914880.

The spelling of 1693661 in words is "one million, six hundred ninety-three thousand, six hundred sixty-one".