1605664665511 has 2 divisors, whose sum is σ = 1605664665512. Its totient is φ = 1605664665510.

The previous prime is 1605664665361. The next prime is 1605664665551. The reversal of 1605664665511 is 1155664665061.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1605664665511 is a prime.

It is a super-2 number, since 2×1605664665511² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1605664665551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 802832332755 + 802832332756.

It is an arithmetic number, because the mean of its divisors is an integer number (802832332756).

Almost surely, 2^{1605664665511} is an apocalyptic number.

1605664665511 is a deficient number, since it is larger than the sum of its proper divisors (1).

1605664665511 is an equidigital number, since it uses as much as digits as its factorization.

1605664665511 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888000, while the sum is 52.

The spelling of 1605664665511 in words is "one trillion, six hundred five billion, six hundred sixty-four million, six hundred sixty-five thousand, five hundred eleven".