66444388 has 6 divisors (see below), whose sum is σ = 116277686. Its totient is φ = 33222192.

The previous prime is 66444383. The next prime is 66444403. The reversal of 66444388 is 88344466.

It can be written as a sum of positive squares in only one way, i.e., 45265984 + 21178404 = 6728^2 + 4602^2 .

It is not an unprimeable number, because it can be changed into a prime (66444383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8305545 + ... + 8305552.

Almost surely, 2^66444388 is an apocalyptic number.

It is an amenable number.

66444388 is a deficient number, since it is larger than the sum of its proper divisors (49833298).

66444388 is a wasteful number, since it uses less digits than its factorization.

66444388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16611101 (or 16611099 counting only the distinct ones).

The product of its digits is 442368, while the sum is 43.

The square root of 66444388 is about 8151.3427114801. The cubic root of 66444388 is about 405.0289833447.

The spelling of 66444388 in words is "sixty-six million, four hundred forty-four thousand, three hundred eighty-eight".