1664871497 has 2 divisors, whose sum is σ = 1664871498. Its totient is φ = 1664871496.

The previous prime is 1664871493. The next prime is 1664871521. The reversal of 1664871497 is 7941784661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1543232656 + 121638841 = 39284^2 + 11029^2 .

It is an emirp because it is prime and its reverse (7941784661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1664871497 - 2² = 1664871493 is a prime.

It is not a weakly prime, because it can be changed into another prime (1664871493) 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, 832435748 + 832435749.

It is an arithmetic number, because the mean of its divisors is an integer number (832435749).

Almost surely, 2^1664871497 is an apocalyptic number.

It is an amenable number.

1664871497 is a deficient number, since it is larger than the sum of its proper divisors (1).

1664871497 is an equidigital number, since it uses as much as digits as its factorization.

1664871497 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2032128, while the sum is 53.

The square root of 1664871497 is about 40802.8368744135. The cubic root of 1664871497 is about 1185.2052667731.

The spelling of 1664871497 in words is "one billion, six hundred sixty-four million, eight hundred seventy-one thousand, four hundred ninety-seven".