218413681 has 8 divisors (see below), whose sum is σ = 228294144. Its totient is φ = 208565280.

The previous prime is 218413651. The next prime is 218413697. The reversal of 218413681 is 186314812.

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 218413681 - 2⁵ = 218413649 is a prime.

It is a super-2 number, since 2×218413681² = 95409072095939522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (218413621) 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 7 ways as a sum of consecutive naturals, for example, 6496 + ... + 21886.

It is an arithmetic number, because the mean of its divisors is an integer number (28536768).

Almost surely, 2^218413681 is an apocalyptic number.

It is an amenable number.

218413681 is a deficient number, since it is larger than the sum of its proper divisors (9880463).

218413681 is a wasteful number, since it uses less digits than its factorization.

218413681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16031.

The product of its digits is 9216, while the sum is 34.

The square root of 218413681 is about 14778.8254269411. The cubic root of 218413681 is about 602.2266165579.

The spelling of 218413681 in words is "two hundred eighteen million, four hundred thirteen thousand, six hundred eighty-one".