66358816 has 24 divisors (see below), whose sum is σ = 130866624. Its totient is φ = 33122880.

The previous prime is 66358813. The next prime is 66358823. The reversal of 66358816 is 61885366.

It is a Smith number, since the sum of its digits (43) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (66358813) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22381 + ... + 25171.

It is an arithmetic number, because the mean of its divisors is an integer number (5452776).

Almost surely, 2^66358816 is an apocalyptic number.

It is an amenable number.

66358816 is a deficient number, since it is larger than the sum of its proper divisors (64507808).

66358816 is a wasteful number, since it uses less digits than its factorization.

66358816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3544 (or 3536 counting only the distinct ones).

The product of its digits is 207360, while the sum is 43.

The square root of 66358816 is about 8146.0920692072. The cubic root of 66358816 is about 404.8550332152.

It can be divided in two parts, 6635 and 8816, that added together give a palindrome (15451).

The spelling of 66358816 in words is "sixty-six million, three hundred fifty-eight thousand, eight hundred sixteen".