66628211 has 4 divisors (see below), whose sum is σ = 71753472. Its totient is φ = 61502952.

The previous prime is 66628189. The next prime is 66628213. The reversal of 66628211 is 11282666.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66628211 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66628213) 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, 2562611 + ... + 2562636.

It is an arithmetic number, because the mean of its divisors is an integer number (17938368).

Almost surely, 2^66628211 is an apocalyptic number.

66628211 is a deficient number, since it is larger than the sum of its proper divisors (5125261).

66628211 is a wasteful number, since it uses less digits than its factorization.

66628211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5125260.

The product of its digits is 6912, while the sum is 32.

The square root of 66628211 is about 8162.6105505531. The cubic root of 66628211 is about 405.4021529983.

The spelling of 66628211 in words is "sixty-six million, six hundred twenty-eight thousand, two hundred eleven".