166720105 has 8 divisors (see below), whose sum is σ = 211832712. Its totient is φ = 125530368.

The previous prime is 166720093. The next prime is 166720129. The reversal of 166720105 is 501027661.

It can be written as a sum of positive squares in 4 ways, for example, as 3825936 + 162894169 = 1956^2 + 12763^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 166720105 - 2⁹ = 166719593 is a prime.

It is a super-2 number, since 2×166720105² = 55591186822422050, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 980622 + ... + 980791.

It is an arithmetic number, because the mean of its divisors is an integer number (26479089).

Almost surely, 2^166720105 is an apocalyptic number.

It is an amenable number.

166720105 is a deficient number, since it is larger than the sum of its proper divisors (45112607).

166720105 is a wasteful number, since it uses less digits than its factorization.

166720105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1961435.

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 166720105 is about 12912.0139792365. The cubic root of 166720105 is about 550.3800183604.

Adding to 166720105 its reverse (501027661), we get a palindrome (667747766).

The spelling of 166720105 in words is "one hundred sixty-six million, seven hundred twenty thousand, one hundred five".