66813983 has 2 divisors, whose sum is σ = 66813984. Its totient is φ = 66813982.

The previous prime is 66813977. The next prime is 66814003. The reversal of 66813983 is 38931866.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66813983 - 2¹² = 66809887 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66813953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33406991 + 33406992.

It is an arithmetic number, because the mean of its divisors is an integer number (33406992).

Almost surely, 2^66813983 is an apocalyptic number.

66813983 is a deficient number, since it is larger than the sum of its proper divisors (1).

66813983 is an equidigital number, since it uses as much as digits as its factorization.

66813983 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 186624, while the sum is 44.

The square root of 66813983 is about 8173.9820772987. The cubic root of 66813983 is about 405.7785825458.

The spelling of 66813983 in words is "sixty-six million, eight hundred thirteen thousand, nine hundred eighty-three".