66646572 has 12 divisors (see below), whose sum is σ = 155508696. Its totient is φ = 22215520.

The previous prime is 66646561. The next prime is 66646627. The reversal of 66646572 is 27564666.

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

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

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, 2776929 + ... + 2776952.

It is an arithmetic number, because the mean of its divisors is an integer number (12959058).

Almost surely, 2^66646572 is an apocalyptic number.

It is an amenable number.

66646572 is an abundant number, since it is smaller than the sum of its proper divisors (88862124).

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

66646572 is a wasteful number, since it uses less digits than its factorization.

66646572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5553888 (or 5553886 counting only the distinct ones).

The product of its digits is 362880, while the sum is 42.

The square root of 66646572 is about 8163.7351745387. The cubic root of 66646572 is about 405.4393890037.

The spelling of 66646572 in words is "sixty-six million, six hundred forty-six thousand, five hundred seventy-two".