66398816 has 24 divisors (see below), whose sum is σ = 142607304. Its totient is φ = 30181120.

The previous prime is 66398747. The next prime is 66398819. The reversal of 66398816 is 61889366.

66398816 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66398819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 93965 + ... + 94668.

It is an arithmetic number, because the mean of its divisors is an integer number (5941971).

Almost surely, 2^66398816 is an apocalyptic number.

It is an amenable number.

66398816 is an abundant number, since it is smaller than the sum of its proper divisors (76208488).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66398816 is a wasteful number, since it uses less digits than its factorization.

66398816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188654 (or 188646 counting only the distinct ones).

The product of its digits is 373248, while the sum is 47.

The square root of 66398816 is about 8148.5468643188. The cubic root of 66398816 is about 404.9363635218.

The spelling of 66398816 in words is "sixty-six million, three hundred ninety-eight thousand, eight hundred sixteen".