66415022881 has 2 divisors, whose sum is σ = 66415022882. Its totient is φ = 66415022880.

The previous prime is 66415022857. The next prime is 66415022897. The reversal of 66415022881 is 18822051466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 37859430625 + 28555592256 = 194575^2 + 168984^2 .

It is a cyclic number.

It is not a de Polignac number, because 66415022881 - 2²⁵ = 66381468449 is a prime.

It is a super-2 number, since 2×66415022881² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66415023881) 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, 33207511440 + 33207511441.

It is an arithmetic number, because the mean of its divisors is an integer number (33207511441).

Almost surely, 2^66415022881 is an apocalyptic number.

It is an amenable number.

66415022881 is a deficient number, since it is larger than the sum of its proper divisors (1).

66415022881 is an equidigital number, since it uses as much as digits as its factorization.

66415022881 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 184320, while the sum is 43.

The spelling of 66415022881 in words is "sixty-six billion, four hundred fifteen million, twenty-two thousand, eight hundred eighty-one".