66821933 has 4 divisors (see below), whose sum is σ = 66844320. Its totient is φ = 66799548.

The previous prime is 66821929. The next prime is 66821947. The reversal of 66821933 is 33912866.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66821933 - 2² = 66821929 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66821333) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5873 + ... + 12966.

It is an arithmetic number, because the mean of its divisors is an integer number (16711080).

Almost surely, 2^66821933 is an apocalyptic number.

It is an amenable number.

66821933 is a deficient number, since it is larger than the sum of its proper divisors (22387).

66821933 is a wasteful number, since it uses less digits than its factorization.

66821933 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22386.

The product of its digits is 46656, while the sum is 38.

The square root of 66821933 is about 8174.4683619181. The cubic root of 66821933 is about 405.7946760422.

The spelling of 66821933 in words is "sixty-six million, eight hundred twenty-one thousand, nine hundred thirty-three".