66306213 has 6 divisors (see below), whose sum is σ = 95775654. Its totient is φ = 44204136.

The previous prime is 66306211. The next prime is 66306221. The reversal of 66306213 is 31260366.

66306213 is a `hidden beast` number, since 6 + 6 + 30 + 621 + 3 = 666.

It can be written as a sum of positive squares in only one way, i.e., 61496964 + 4809249 = 7842^2 + 2193^2 .

It is not a de Polignac number, because 66306213 - 2¹ = 66306211 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66306211) 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, 3683670 + ... + 3683687.

It is an arithmetic number, because the mean of its divisors is an integer number (15962609).

Almost surely, 2^66306213 is an apocalyptic number.

It is an amenable number.

66306213 is a deficient number, since it is larger than the sum of its proper divisors (29469441).

66306213 is a wasteful number, since it uses less digits than its factorization.

66306213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7367363 (or 7367360 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 27.

The square root of 66306213 is about 8142.8627030056. The cubic root of 66306213 is about 404.7480279953.

Adding to 66306213 its reverse (31260366), we get a palindrome (97566579).

The spelling of 66306213 in words is "sixty-six million, three hundred six thousand, two hundred thirteen".