166625187 has 4 divisors (see below), whose sum is σ = 222166920. Its totient is φ = 111083456.

The previous prime is 166625131. The next prime is 166625191. The reversal of 166625187 is 781526661.

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

It is a cyclic number.

It is not a de Polignac number, because 166625187 - 2¹⁶ = 166559651 is a prime.

It is not an unprimeable number, because it can be changed into a prime (166625197) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27770862 + ... + 27770867.

It is an arithmetic number, because the mean of its divisors is an integer number (55541730).

Almost surely, 2^166625187 is an apocalyptic number.

166625187 is a deficient number, since it is larger than the sum of its proper divisors (55541733).

166625187 is an equidigital number, since it uses as much as digits as its factorization.

166625187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55541732.

The product of its digits is 120960, while the sum is 42.

The square root of 166625187 is about 12908.3378868079. The cubic root of 166625187 is about 550.2755500806.

The spelling of 166625187 in words is "one hundred sixty-six million, six hundred twenty-five thousand, one hundred eighty-seven".