66689964 has 36 divisors (see below), whose sum is σ = 183903720. Its totient is φ = 20208960.

The previous prime is 66689957. The next prime is 66689969. The reversal of 66689964 is 46998666.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (36).

It is a self number, because there is not a number n which added to its sum of digits gives 66689964.

It is not an unprimeable number, because it can be changed into a prime (66689969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 83809 + ... + 84600.

Almost surely, 2^66689964 is an apocalyptic number.

It is an amenable number.

66689964 is an abundant number, since it is smaller than the sum of its proper divisors (117213756).

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

66689964 is a wasteful number, since it uses less digits than its factorization.

66689964 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168430 (or 168425 counting only the distinct ones).

The product of its digits is 3359232, while the sum is 54.

The square root of 66689964 is about 8166.3923491343. The cubic root of 66689964 is about 405.5273605664.

The spelling of 66689964 in words is "sixty-six million, six hundred eighty-nine thousand, nine hundred sixty-four".