66277881 has 18 divisors (see below), whose sum is σ = 100085258. Its totient is φ = 42261120.

The previous prime is 66277879. The next prime is 66277889. The reversal of 66277881 is 18877266.

It can be written as a sum of positive squares in only one way, i.e., 58660281 + 7617600 = 7659^2 + 2760^2 .

It is not a de Polignac number, because 66277881 - 2¹ = 66277879 is a prime.

It is a super-2 number, since 2×66277881² = 8785515019700322, which 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 (66277889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 2200 + ... + 11721.

Almost surely, 2^66277881 is an apocalyptic number.

It is an amenable number.

66277881 is a deficient number, since it is larger than the sum of its proper divisors (33807377).

66277881 is a wasteful number, since it uses less digits than its factorization.

66277881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13973 (or 13947 counting only the distinct ones).

The product of its digits is 225792, while the sum is 45.

The square root of 66277881 is about 8141.1228341059. The cubic root of 66277881 is about 404.6903714837.

The spelling of 66277881 in words is "sixty-six million, two hundred seventy-seven thousand, eight hundred eighty-one".