1665973 has 2 divisors, whose sum is σ = 1665974. Its totient is φ = 1665972.

The previous prime is 1665967. The next prime is 1665997. The reversal of 1665973 is 3795661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1656369 + 9604 = 1287^2 + 98^2 .

It is an emirp because it is prime and its reverse (3795661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1665973 - 2⁵ = 1665941 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1665943) 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, 832986 + 832987.

It is an arithmetic number, because the mean of its divisors is an integer number (832987).

2^1665973 is an apocalyptic number.

It is an amenable number.

1665973 is a deficient number, since it is larger than the sum of its proper divisors (1).

1665973 is an equidigital number, since it uses as much as digits as its factorization.

1665973 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34020, while the sum is 37.

The square root of 1665973 is about 1290.7257648316. The cubic root of 1665973 is about 118.5466592117.

The spelling of 1665973 in words is "one million, six hundred sixty-five thousand, nine hundred seventy-three".