66353818 has 4 divisors (see below), whose sum is σ = 99530730. Its totient is φ = 33176908.

The previous prime is 66353813. The next prime is 66353821. The reversal of 66353818 is 81835366.

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

It can be written as a sum of positive squares in only one way, i.e., 66308449 + 45369 = 8143^2 + 213^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (66353813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16588453 + ... + 16588456.

Almost surely, 2^66353818 is an apocalyptic number.

66353818 is a deficient number, since it is larger than the sum of its proper divisors (33176912).

66353818 is a wasteful number, since it uses less digits than its factorization.

66353818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33176911.

The product of its digits is 103680, while the sum is 40.

The square root of 66353818 is about 8145.7852905659. The cubic root of 66353818 is about 404.8448686966.

The spelling of 66353818 in words is "sixty-six million, three hundred fifty-three thousand, eight hundred eighteen".