166516225 has 6 divisors (see below), whose sum is σ = 206480150. Its totient is φ = 133212960.

The previous prime is 166516223. The next prime is 166516237. The reversal of 166516225 is 522615661.

It can be written as a sum of positive squares in 3 ways, for example, as 28430224 + 138086001 = 5332^2 + 11751^2 .

It is not a de Polignac number, because 166516225 - 2¹ = 166516223 is a prime.

It is not an unprimeable number, because it can be changed into a prime (166516223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3330300 + ... + 3330349.

Almost surely, 2^166516225 is an apocalyptic number.

It is an amenable number.

166516225 is a deficient number, since it is larger than the sum of its proper divisors (39963925).

166516225 is an equidigital number, since it uses as much as digits as its factorization.

166516225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6660659 (or 6660654 counting only the distinct ones).

The product of its digits is 21600, while the sum is 34.

The square root of 166516225 is about 12904.1165912278. The cubic root of 166516225 is about 550.1555758236.

The spelling of 166516225 in words is "one hundred sixty-six million, five hundred sixteen thousand, two hundred twenty-five".