166120645 has 4 divisors (see below), whose sum is σ = 199344780. Its totient is φ = 132896512.

The previous prime is 166120631. The next prime is 166120649. The reversal of 166120645 is 546021661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 66080641 + 100040004 = 8129^2 + 10002^2 .

It is a cyclic number.

It is not a de Polignac number, because 166120645 - 2⁷ = 166120517 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166120649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16612060 + ... + 16612069.

It is an arithmetic number, because the mean of its divisors is an integer number (49836195).

Almost surely, 2^166120645 is an apocalyptic number.

It is an amenable number.

166120645 is a deficient number, since it is larger than the sum of its proper divisors (33224135).

166120645 is an equidigital number, since it uses as much as digits as its factorization.

166120645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33224134.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 166120645 is about 12888.7798103622. The cubic root of 166120645 is about 549.7195760551.

The spelling of 166120645 in words is "one hundred sixty-six million, one hundred twenty thousand, six hundred forty-five".