66666688888873 has 2 divisors, whose sum is σ = 66666688888874. Its totient is φ = 66666688888872.

The previous prime is 66666688888831. The next prime is 66666688888901. The reversal of 66666688888873 is 37888888666666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 52697610713344 + 13969078175529 = 7259312^2 + 3737523^2 .

It is a cyclic number.

It is not a de Polignac number, because 66666688888873 - 2²⁵ = 66666655334441 is a prime.

It is not a weakly prime, because it can be changed into another prime (66666688888073) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33333344444436 + 33333344444437.

It is an arithmetic number, because the mean of its divisors is an integer number (33333344444437).

Almost surely, 2^{66666688888873} is an apocalyptic number.

It is an amenable number.

66666688888873 is a deficient number, since it is larger than the sum of its proper divisors (1).

66666688888873 is an equidigital number, since it uses as much as digits as its factorization.

66666688888873 is an evil number, because the sum of its binary digits is even.

The product of its digits is 256842399744, while the sum is 94.

The spelling of 66666688888873 in words is "sixty-six trillion, six hundred sixty-six billion, six hundred eighty-eight million, eight hundred eighty-eight thousand, eight hundred seventy-three".