166720541 has 8 divisors (see below), whose sum is σ = 180478200. Its totient is φ = 153096192.

The previous prime is 166720531. The next prime is 166720577. The reversal of 166720541 is 145027661.

It can be written as a sum of positive squares in 4 ways, for example, as 22600516 + 144120025 = 4754^2 + 12005^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166720541 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 166720498 and 166720507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166720531) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30716 + ... + 35733.

It is an arithmetic number, because the mean of its divisors is an integer number (22559775).

Almost surely, 2^166720541 is an apocalyptic number.

It is an amenable number.

166720541 is a deficient number, since it is larger than the sum of its proper divisors (13757659).

166720541 is a wasteful number, since it uses less digits than its factorization.

166720541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66655.

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 166720541 is about 12912.0308627264. The cubic root of 166720541 is about 550.3804981376.

The spelling of 166720541 in words is "one hundred sixty-six million, seven hundred twenty thousand, five hundred forty-one".