66216442 has 16 divisors (see below), whose sum is σ = 100482912. Its totient is φ = 32724720.

The previous prime is 66216433. The next prime is 66216443. The reversal of 66216442 is 24461266.

It is a super-2 number, since 2×66216442² = 8769234382278728, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66216443) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 72553 + ... + 73459.

It is an arithmetic number, because the mean of its divisors is an integer number (6280182).

Almost surely, 2^66216442 is an apocalyptic number.

66216442 is a deficient number, since it is larger than the sum of its proper divisors (34266470).

66216442 is a wasteful number, since it uses less digits than its factorization.

66216442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1293.

The product of its digits is 13824, while the sum is 31.

The square root of 66216442 is about 8137.3485853809. The cubic root of 66216442 is about 404.5652847119.

The spelling of 66216442 in words is "sixty-six million, two hundred sixteen thousand, four hundred forty-two".