66820669783983 has 28 divisors (see below), whose sum is σ = 100634435428800. Its totient is φ = 44347350242016.

The previous prime is 66820669783963. The next prime is 66820669784051. The reversal of 66820669783983 is 38938796602866.

66820669783983 is a `hidden beast` number, since 6 + 6 + 82 + 0 + 66 + 97 + 8 + 398 + 3 = 666.

It is not a de Polignac number, because 66820669783983 - 2¹⁰ = 66820669782959 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66820669783913) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 205354758 + ... + 205679891.

It is an arithmetic number, because the mean of its divisors is an integer number (3594086979600).

Almost surely, 2^{66820669783983} is an apocalyptic number.

66820669783983 is a deficient number, since it is larger than the sum of its proper divisors (33813765644817).

66820669783983 is an equidigital number, since it uses as much as digits as its factorization.

66820669783983 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 411034890 (or 411034875 counting only the distinct ones).

The product of its (nonzero) digits is 6772211712, while the sum is 81.

The spelling of 66820669783983 in words is "sixty-six trillion, eight hundred twenty billion, six hundred sixty-nine million, seven hundred eighty-three thousand, nine hundred eighty-three".