1663693 has 2 divisors, whose sum is σ = 1663694. Its totient is φ = 1663692.

The previous prime is 1663687. The next prime is 1663703. The reversal of 1663693 is 3963661.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1225449 + 438244 = 1107^2 + 662^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1663693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1663793) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 831846 + 831847.

It is an arithmetic number, because the mean of its divisors is an integer number (831847).

2^1663693 is an apocalyptic number.

It is an amenable number.

1663693 is a deficient number, since it is larger than the sum of its proper divisors (1).

1663693 is an equidigital number, since it uses as much as digits as its factorization.

1663693 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17496, while the sum is 34.

The square root of 1663693 is about 1289.8422384152. The cubic root of 1663693 is about 118.4925547377.

Subtracting 1663693 from its reverse (3963661), we obtain a cube (2299968 = 132³).

The spelling of 1663693 in words is "one million, six hundred sixty-three thousand, six hundred ninety-three".