218666481 has 24 divisors (see below), whose sum is σ = 327946080. Its totient is φ = 129433920.

The previous prime is 218666479. The next prime is 218666507. The reversal of 218666481 is 184666812.

It is not a de Polignac number, because 218666481 - 2¹ = 218666479 is a prime.

It is a super-2 number, since 2×218666481² = 95630059825846722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (218666471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8605 + ... + 22613.

It is an arithmetic number, because the mean of its divisors is an integer number (13664420).

Almost surely, 2^218666481 is an apocalyptic number.

It is an amenable number.

218666481 is a deficient number, since it is larger than the sum of its proper divisors (109279599).

218666481 is a wasteful number, since it uses less digits than its factorization.

218666481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14077 (or 14066 counting only the distinct ones).

The product of its digits is 110592, while the sum is 42.

The square root of 218666481 is about 14787.3757306697. The cubic root of 218666481 is about 602.4588733600.

The spelling of 218666481 in words is "two hundred eighteen million, six hundred sixty-six thousand, four hundred eighty-one".