66888888888881 has 2 divisors, whose sum is σ = 66888888888882. Its totient is φ = 66888888888880.

The previous prime is 66888888888839. The next prime is 66888888889021. The reversal of 66888888888881 is 18888888888866.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 57502116490225 + 9386772398656 = 7583015^2 + 3063784^2 .

It is a cyclic number.

It is not a de Polignac number, because 66888888888881 - 2⁶ = 66888888888817 is a prime.

It is a super-2 number, since 2×66888888888881² (a number of 28 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66888888888281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33444444444440 + 33444444444441.

It is an arithmetic number, because the mean of its divisors is an integer number (33444444444441).

Almost surely, 2^{66888888888881} is an apocalyptic number.

It is an amenable number.

66888888888881 is a deficient number, since it is larger than the sum of its proper divisors (1).

66888888888881 is an equidigital number, since it uses as much as digits as its factorization.

66888888888881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 309237645312, while the sum is 101.

The spelling of 66888888888881 in words is "sixty-six trillion, eight hundred eighty-eight billion, eight hundred eighty-eight million, eight hundred eighty-eight thousand, eight hundred eighty-one".