1659997 has 2 divisors, whose sum is σ = 1659998. Its totient is φ = 1659996.

The previous prime is 1659971. The next prime is 1660007. The reversal of 1659997 is 7999561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1110916 + 549081 = 1054^2 + 741^2 .

It is a cyclic number.

It is not a de Polignac number, because 1659997 - 2¹¹ = 1657949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1659797) 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, 829998 + 829999.

It is an arithmetic number, because the mean of its divisors is an integer number (829999).

2^1659997 is an apocalyptic number.

It is an amenable number.

1659997 is a deficient number, since it is larger than the sum of its proper divisors (1).

1659997 is an equidigital number, since it uses as much as digits as its factorization.

1659997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 153090, while the sum is 46.

The square root of 1659997 is about 1288.4087084462. The cubic root of 1659997 is about 118.4047434260.

The spelling of 1659997 in words is "one million, six hundred fifty-nine thousand, nine hundred ninety-seven".