66983821 has 8 divisors (see below), whose sum is σ = 68624640. Its totient is φ = 65359968.

The previous prime is 66983783. The next prime is 66983827. The reversal of 66983821 is 12838966.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66983821 - 2¹⁷ = 66852749 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 (66983827) 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 7 ways as a sum of consecutive naturals, for example, 3940 + ... + 12226.

It is an arithmetic number, because the mean of its divisors is an integer number (8578080).

Almost surely, 2^66983821 is an apocalyptic number.

It is an amenable number.

66983821 is a deficient number, since it is larger than the sum of its proper divisors (1640819).

66983821 is a wasteful number, since it uses less digits than its factorization.

66983821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8483.

The product of its digits is 124416, while the sum is 43.

The square root of 66983821 is about 8184.3644224827. The cubic root of 66983821 is about 406.1221149815.

The spelling of 66983821 in words is "sixty-six million, nine hundred eighty-three thousand, eight hundred twenty-one".