11661565164655 has 16 divisors (see below), whose sum is σ = 16063457425920. Its totient is φ = 7961274941472.

The previous prime is 11661565164653. The next prime is 11661565164679. The reversal of 11661565164655 is 55646156516611.

It is a cyclic number.

It is not a de Polignac number, because 11661565164655 - 2¹ = 11661565164653 is a prime.

It is a super-2 number, since 2×11661565164655² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 11661565164655.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11661565164653) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 733885395 + ... + 733901284.

It is an arithmetic number, because the mean of its divisors is an integer number (1003966089120).

Almost surely, 2^{11661565164655} is an apocalyptic number.

11661565164655 is a deficient number, since it is larger than the sum of its proper divisors (4401892261265).

11661565164655 is a wasteful number, since it uses less digits than its factorization.

11661565164655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1467786918.

The product of its digits is 19440000, while the sum is 58.

The spelling of 11661565164655 in words is "eleven trillion, six hundred sixty-one billion, five hundred sixty-five million, one hundred sixty-four thousand, six hundred fifty-five".