66564219 has 4 divisors (see below), whose sum is σ = 88752296. Its totient is φ = 44376144.

The previous prime is 66564209. The next prime is 66564233. The reversal of 66564219 is 91246566.

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

It is not a de Polignac number, because 66564219 - 2⁵ = 66564187 is a prime.

It is a super-2 number, since 2×66564219² = 8861590502159922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66564209) 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, 11094034 + ... + 11094039.

It is an arithmetic number, because the mean of its divisors is an integer number (22188074).

Almost surely, 2^66564219 is an apocalyptic number.

66564219 is a deficient number, since it is larger than the sum of its proper divisors (22188077).

66564219 is a wasteful number, since it uses less digits than its factorization.

66564219 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22188076.

The product of its digits is 77760, while the sum is 39.

The square root of 66564219 is about 8158.6897845181. The cubic root of 66564219 is about 405.2723240866.

The spelling of 66564219 in words is "sixty-six million, five hundred sixty-four thousand, two hundred nineteen".