166213645 has 16 divisors (see below), whose sum is σ = 222208560. Its totient is φ = 118508544.

The previous prime is 166213643. The next prime is 166213669. The reversal of 166213645 is 546312661.

It can be written as a sum of positive squares in 8 ways, for example, as 5963364 + 160250281 = 2442^2 + 12659^2 .

It is a cyclic number.

It is not a de Polignac number, because 166213645 - 2¹ = 166213643 is a prime.

It is a super-3 number, since 3×166213645³ (a number of 26 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 166213645.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166213643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42204 + ... + 45973.

It is an arithmetic number, because the mean of its divisors is an integer number (13888035).

Almost surely, 2^166213645 is an apocalyptic number.

It is an amenable number.

166213645 is a deficient number, since it is larger than the sum of its proper divisors (55994915).

166213645 is a wasteful number, since it uses less digits than its factorization.

166213645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88224.

The product of its digits is 25920, while the sum is 34.

The square root of 166213645 is about 12892.3870947160. The cubic root of 166213645 is about 549.8221408372.

The spelling of 166213645 in words is "one hundred sixty-six million, two hundred thirteen thousand, six hundred forty-five".