1665455969 has 2 divisors, whose sum is σ = 1665455970. Its totient is φ = 1665455968.

The previous prime is 1665455867. The next prime is 1665455989. The reversal of 1665455969 is 9695545661.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 887324944 + 778131025 = 29788^2 + 27895^2 .

It is an emirp because it is prime and its reverse (9695545661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1665455969 - 2⁸ = 1665455713 is a prime.

It is a super-2 number, since 2×1665455969² = 5547487169355457922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1665455989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832727984 + 832727985.

It is an arithmetic number, because the mean of its divisors is an integer number (832727985).

Almost surely, 2^1665455969 is an apocalyptic number.

It is an amenable number.

1665455969 is a deficient number, since it is larger than the sum of its proper divisors (1).

1665455969 is an equidigital number, since it uses as much as digits as its factorization.

1665455969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8748000, while the sum is 56.

The square root of 1665455969 is about 40809.9983950012. The cubic root of 1665455969 is about 1185.3439437916.

The spelling of 1665455969 in words is "one billion, six hundred sixty-five million, four hundred fifty-five thousand, nine hundred sixty-nine".