166656105561 has 16 divisors (see below), whose sum is σ = 242507021760. Its totient is φ = 100962808320.

The previous prime is 166656105541. The next prime is 166656105571. The reversal of 166656105561 is 165501656661.

It is not a de Polignac number, because 166656105561 - 2¹¹ = 166656103513 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 166656105561.

It is not an unprimeable number, because it can be changed into a prime (166656105541) 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, 939456 + ... + 1102673.

It is an arithmetic number, because the mean of its divisors is an integer number (15156688860).

Almost surely, 2^166656105561 is an apocalyptic number.

166656105561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

166656105561 is a deficient number, since it is larger than the sum of its proper divisors (75850916199).

166656105561 is a wasteful number, since it uses less digits than its factorization.

166656105561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2044616.

The product of its (nonzero) digits is 972000, while the sum is 48.

The spelling of 166656105561 in words is "one hundred sixty-six billion, six hundred fifty-six million, one hundred five thousand, five hundred sixty-one".