2218636881 has 6 divisors (see below), whose sum is σ = 3204697730. Its totient is φ = 1479091248.

The previous prime is 2218636853. The next prime is 2218636907. The reversal of 2218636881 is 1886368122.

2218636881 is a `hidden beast` number, since 2 + 2 + 1 + 8 + 636 + 8 + 8 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1418652225 + 799984656 = 37665^2 + 28284^2 .

It is not a de Polignac number, because 2218636881 - 2¹¹ = 2218634833 is a prime.

It is a super-2 number, since 2×2218636881² = 9844699219466816322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2218636811) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 123257596 + ... + 123257613.

Almost surely, 2^2218636881 is an apocalyptic number.

It is an amenable number.

2218636881 is a deficient number, since it is larger than the sum of its proper divisors (986060849).

2218636881 is a wasteful number, since it uses less digits than its factorization.

2218636881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 246515215 (or 246515212 counting only the distinct ones).

The product of its digits is 221184, while the sum is 45.

The square root of 2218636881 is about 47102.4084416073. The cubic root of 2218636881 is about 1304.2536958017.

The spelling of 2218636881 in words is "two billion, two hundred eighteen million, six hundred thirty-six thousand, eight hundred eighty-one".