66439286181 has 20 divisors (see below), whose sum is σ = 99371286784. Its totient is φ = 44238198600.

The previous prime is 66439286159. The next prime is 66439286227. The reversal of 66439286181 is 18168293466.

66439286181 is a `hidden beast` number, since 6 + 6 + 439 + 28 + 6 + 181 = 666.

It is not a de Polignac number, because 66439286181 - 2⁹ = 66439285669 is a prime.

It is a super-2 number, since 2×66439286181² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66439286131) 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 in 19 ways as a sum of consecutive naturals, for example, 440005 + ... + 571386.

Almost surely, 2^66439286181 is an apocalyptic number.

It is an amenable number.

66439286181 is a deficient number, since it is larger than the sum of its proper divisors (32932000603).

66439286181 is a wasteful number, since it uses less digits than its factorization.

66439286181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1012214 (or 1012205 counting only the distinct ones).

The product of its digits is 2985984, while the sum is 54.

The spelling of 66439286181 in words is "sixty-six billion, four hundred thirty-nine million, two hundred eighty-six thousand, one hundred eighty-one".