1664183021 has 2 divisors, whose sum is σ = 1664183022. Its totient is φ = 1664183020.

The previous prime is 1664183011. The next prime is 1664183041. The reversal of 1664183021 is 1203814661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1521858121 + 142324900 = 39011^2 + 11930^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1664183021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1664183011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832091510 + 832091511.

It is an arithmetic number, because the mean of its divisors is an integer number (832091511).

Almost surely, 2^1664183021 is an apocalyptic number.

It is an amenable number.

1664183021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1664183021 is an equidigital number, since it uses as much as digits as its factorization.

1664183021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 1664183021 is about 40794.3993827584. The cubic root of 1664183021 is about 1185.0418712023.

Adding to 1664183021 its reverse (1203814661), we get a palindrome (2867997682).

The spelling of 1664183021 in words is "one billion, six hundred sixty-four million, one hundred eighty-three thousand, twenty-one".