66316816 has 10 divisors (see below), whose sum is σ = 128488862. Its totient is φ = 33158400.

The previous prime is 66316759. The next prime is 66316819. The reversal of 66316816 is 61861366.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 33872400 + 32444416 = 5820^2 + 5696^2 .

It is not an unprimeable number, because it can be changed into a prime (66316819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2072385 + ... + 2072416.

Almost surely, 2^66316816 is an apocalyptic number.

It is an amenable number.

66316816 is a deficient number, since it is larger than the sum of its proper divisors (62172046).

66316816 is a wasteful number, since it uses less digits than its factorization.

66316816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4144809 (or 4144803 counting only the distinct ones).

The product of its digits is 31104, while the sum is 37.

The square root of 66316816 is about 8143.5137379389. The cubic root of 66316816 is about 404.7696012105.

The spelling of 66316816 in words is "sixty-six million, three hundred sixteen thousand, eight hundred sixteen".