12166556156161 has 4 divisors (see below), whose sum is σ = 13272606715824. Its totient is φ = 11060505596500.

The previous prime is 12166556156123. The next prime is 12166556156267. The reversal of 12166556156161 is 16165165566121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12166556156161 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12166556156099 and 12166556156108.

It is not an unprimeable number, because it can be changed into a prime (12166556156101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 553025279815 + ... + 553025279836.

It is an arithmetic number, because the mean of its divisors is an integer number (3318151678956).

Almost surely, 2^{12166556156161} is an apocalyptic number.

12166556156161 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12166556156161 is a deficient number, since it is larger than the sum of its proper divisors (1106050559663).

12166556156161 is a wasteful number, since it uses less digits than its factorization.

12166556156161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1106050559662.

The product of its digits is 1944000, while the sum is 52.

The spelling of 12166556156161 in words is "twelve trillion, one hundred sixty-six billion, five hundred fifty-six million, one hundred fifty-six thousand, one hundred sixty-one".