66691608 has 32 divisors (see below), whose sum is σ = 167017200. Its totient is φ = 22192128.

The previous prime is 66691591. The next prime is 66691609. The reversal of 66691608 is 80619666.

66691608 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 66691608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66691609) 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 7 ways as a sum of consecutive naturals, for example, 14088 + ... + 18216.

Almost surely, 2^66691608 is an apocalyptic number.

It is an amenable number.

66691608 is an abundant number, since it is smaller than the sum of its proper divisors (100325592).

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

66691608 is a wasteful number, since it uses less digits than its factorization.

66691608 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4811 (or 4807 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 42.

The square root of 66691608 is about 8166.4930049563. The cubic root of 66691608 is about 405.5306928094.

The spelling of 66691608 in words is "sixty-six million, six hundred ninety-one thousand, six hundred eight".