166511106605 has 4 divisors (see below), whose sum is σ = 199813327932. Its totient is φ = 133208885280.

The previous prime is 166511106581. The next prime is 166511106617. The reversal of 166511106605 is 506601115661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 506601115661 = 76129 ⋅6654509.

It can be written as a sum of positive squares in 2 ways, for example, as 39209148169 + 127301958436 = 198013^2 + 356794^2 .

It is a de Polignac number, because none of the positive numbers 2^k-166511106605 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16651110656 + ... + 16651110665.

It is an arithmetic number, because the mean of its divisors is an integer number (49953331983).

Almost surely, 2^166511106605 is an apocalyptic number.

It is an amenable number.

166511106605 is a deficient number, since it is larger than the sum of its proper divisors (33302221327).

166511106605 is an equidigital number, since it uses as much as digits as its factorization.

166511106605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33302221326.

The product of its (nonzero) digits is 32400, while the sum is 38.

The spelling of 166511106605 in words is "one hundred sixty-six billion, five hundred eleven million, one hundred six thousand, six hundred five".