66681671453 has 2 divisors, whose sum is σ = 66681671454. Its totient is φ = 66681671452.

The previous prime is 66681671443. The next prime is 66681671477. The reversal of 66681671453 is 35417618666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49941969529 + 16739701924 = 223477^2 + 129382^2 .

It is a cyclic number.

It is not a de Polignac number, because 66681671453 - 2⁸ = 66681671197 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66681671395 and 66681671404.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66681671443) 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 as a sum of consecutive naturals, namely, 33340835726 + 33340835727.

It is an arithmetic number, because the mean of its divisors is an integer number (33340835727).

Almost surely, 2^66681671453 is an apocalyptic number.

It is an amenable number.

66681671453 is a deficient number, since it is larger than the sum of its proper divisors (1).

66681671453 is an equidigital number, since it uses as much as digits as its factorization.

66681671453 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4354560, while the sum is 53.

The spelling of 66681671453 in words is "sixty-six billion, six hundred eighty-one million, six hundred seventy-one thousand, four hundred fifty-three".