1665116549 has 2 divisors, whose sum is σ = 1665116550. Its totient is φ = 1665116548.

The previous prime is 1665116501. The next prime is 1665116567. The reversal of 1665116549 is 9456115661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1290964900 + 374151649 = 35930^2 + 19343^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1665116549 is a prime.

It is a super-2 number, since 2×1665116549² = 5545226243507338802, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1665116569) 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, 832558274 + 832558275.

It is an arithmetic number, because the mean of its divisors is an integer number (832558275).

Almost surely, 2^1665116549 is an apocalyptic number.

It is an amenable number.

1665116549 is a deficient number, since it is larger than the sum of its proper divisors (1).

1665116549 is an equidigital number, since it uses as much as digits as its factorization.

1665116549 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 194400, while the sum is 44.

The square root of 1665116549 is about 40805.8396433648. The cubic root of 1665116549 is about 1185.2634139380.

The spelling of 1665116549 in words is "one billion, six hundred sixty-five million, one hundred sixteen thousand, five hundred forty-nine".