66688836 has 12 divisors (see below), whose sum is σ = 155607312. Its totient is φ = 22229608.

The previous prime is 66688813. The next prime is 66688847. The reversal of 66688836 is 63888666.

It is a tau number, because it is divible by the number of its divisors (12).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2778690 + ... + 2778713.

It is an arithmetic number, because the mean of its divisors is an integer number (12967276).

Almost surely, 2^66688836 is an apocalyptic number.

It is an amenable number.

66688836 is an abundant number, since it is smaller than the sum of its proper divisors (88918476).

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

66688836 is a wasteful number, since it uses less digits than its factorization.

66688836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5557410 (or 5557408 counting only the distinct ones).

The product of its digits is 1990656, while the sum is 51.

The square root of 66688836 is about 8166.3232852980. The cubic root of 66688836 is about 405.5250741782.

The spelling of 66688836 in words is "sixty-six million, six hundred eighty-eight thousand, eight hundred thirty-six".