66166225 has 6 divisors (see below), whose sum is σ = 82046150. Its totient is φ = 52932960.

The previous prime is 66166223. The next prime is 66166229. The reversal of 66166225 is 52266166.

It can be written as a sum of positive squares in 3 ways, for example, as 1669264 + 64496961 = 1292^2 + 8031^2 .

It is not a de Polignac number, because 66166225 - 2¹ = 66166223 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66166223) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1323300 + ... + 1323349.

Almost surely, 2^66166225 is an apocalyptic number.

It is an amenable number.

66166225 is a deficient number, since it is larger than the sum of its proper divisors (15879925).

66166225 is a wasteful number, since it uses less digits than its factorization.

66166225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2646659 (or 2646654 counting only the distinct ones).

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

The square root of 66166225 is about 8134.2624127821. The cubic root of 66166225 is about 404.4629878997.

The spelling of 66166225 in words is "sixty-six million, one hundred sixty-six thousand, two hundred twenty-five".