166620077172 has 18 divisors (see below), whose sum is σ = 421178528498. Its totient is φ = 55540025712.

The previous prime is 166620077159. The next prime is 166620077177. The reversal of 166620077172 is 271770026661.

166620077172 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 165945428496 + 674648676 = 407364^2 + 25974^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166620077177) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2314167703 + ... + 2314167774.

Almost surely, 2^166620077172 is an apocalyptic number.

166620077172 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

166620077172 is an abundant number, since it is smaller than the sum of its proper divisors (254558451326).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

166620077172 is a wasteful number, since it uses less digits than its factorization.

166620077172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4628335487 (or 4628335482 counting only the distinct ones).

The product of its (nonzero) digits is 296352, while the sum is 45.

The spelling of 166620077172 in words is "one hundred sixty-six billion, six hundred twenty million, seventy-seven thousand, one hundred seventy-two".