218718481 has 8 divisors (see below), whose sum is σ = 243773280. Its totient is φ = 195018048.

The previous prime is 218718473. The next prime is 218718499. The reversal of 218718481 is 184817812.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 218718481 - 2³ = 218718473 is a prime.

It is a super-2 number, since 2×218718481² = 95675547861894722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (218718281) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 338251 + ... + 338896.

It is an arithmetic number, because the mean of its divisors is an integer number (30471660).

Almost surely, 2^218718481 is an apocalyptic number.

It is an amenable number.

218718481 is a deficient number, since it is larger than the sum of its proper divisors (25054799).

218718481 is a wasteful number, since it uses less digits than its factorization.

218718481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 677183.

The product of its digits is 28672, while the sum is 40.

The square root of 218718481 is about 14789.1338826856. The cubic root of 218718481 is about 602.5066255018.

The spelling of 218718481 in words is "two hundred eighteen million, seven hundred eighteen thousand, four hundred eighty-one".