11661555505156 has 24 divisors (see below), whose sum is σ = 20695436072640. Its totient is φ = 5748576002400.

The previous prime is 11661555505079. The next prime is 11661555505157. The reversal of 11661555505156 is 65150555516611.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (11661555505157) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24535375 + ... + 25006153.

It is an arithmetic number, because the mean of its divisors is an integer number (862309836360).

Almost surely, 2^{11661555505156} is an apocalyptic number.

It is an amenable number.

11661555505156 is a deficient number, since it is larger than the sum of its proper divisors (9033880567484).

11661555505156 is a wasteful number, since it uses less digits than its factorization.

11661555505156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 558075 (or 558073 counting only the distinct ones).

The product of its (nonzero) digits is 3375000, while the sum is 52.

The spelling of 11661555505156 in words is "eleven trillion, six hundred sixty-one billion, five hundred fifty-five million, five hundred five thousand, one hundred fifty-six".