166557721761704 has 128 divisors (see below), whose sum is σ = 387973877760000. Its totient is φ = 65272182393600.

The previous prime is 166557721761689. The next prime is 166557721761707. The reversal of 166557721761704 is 407167127755661.

166557721761704 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (166557721761707) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2582298047 + ... + 2582362545.

It is an arithmetic number, because the mean of its divisors is an integer number (3031045920000).

Almost surely, 2^{166557721761704} is an apocalyptic number.

166557721761704 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 166557721761704, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (193986938880000).

166557721761704 is an abundant number, since it is smaller than the sum of its proper divisors (221416155998296).

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

166557721761704 is a wasteful number, since it uses less digits than its factorization.

166557721761704 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97783 (or 97779 counting only the distinct ones).

The product of its (nonzero) digits is 103723200, while the sum is 65.

The spelling of 166557721761704 in words is "one hundred sixty-six trillion, five hundred fifty-seven billion, seven hundred twenty-one million, seven hundred sixty-one thousand, seven hundred four".