66666245 has 4 divisors (see below), whose sum is σ = 79999500. Its totient is φ = 53332992.

The previous prime is 66666239. The next prime is 66666247. The reversal of 66666245 is 54266666.

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 11282881 + 55383364 = 3359^2 + 7442^2 .

It is a cyclic number.

It is not a de Polignac number, because 66666245 - 2¹² = 66662149 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66666247) 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, 6666620 + ... + 6666629.

It is an arithmetic number, because the mean of its divisors is an integer number (19999875).

Almost surely, 2^66666245 is an apocalyptic number.

It is an amenable number.

66666245 is a deficient number, since it is larger than the sum of its proper divisors (13333255).

66666245 is a wasteful number, since it uses less digits than its factorization.

66666245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13333254.

The product of its digits is 311040, while the sum is 41.

The square root of 66666245 is about 8164.9399875321. The cubic root of 66666245 is about 405.4792781491.

The spelling of 66666245 in words is "sixty-six million, six hundred sixty-six thousand, two hundred forty-five".