66216418 has 8 divisors (see below), whose sum is σ = 100203948. Its totient is φ = 32815104.

The previous prime is 66216413. The next prime is 66216427. The reversal of 66216418 is 81461266.

It can be written as a sum of positive squares in 2 ways, for example, as 65983129 + 233289 = 8123^2 + 483^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×66216418² = 8769228025501448, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66216413) 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, 146271 + ... + 146722.

Almost surely, 2^66216418 is an apocalyptic number.

66216418 is a deficient number, since it is larger than the sum of its proper divisors (33987530).

66216418 is a wasteful number, since it uses less digits than its factorization.

66216418 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 293108.

The product of its digits is 13824, while the sum is 34.

The square root of 66216418 is about 8137.3471106989. The cubic root of 66216418 is about 404.5652358340.

The spelling of 66216418 in words is "sixty-six million, two hundred sixteen thousand, four hundred eighteen".