218686261 has 8 divisors (see below), whose sum is σ = 226290240. Its totient is φ = 211196832.

The previous prime is 218686241. The next prime is 218686309. The reversal of 218686261 is 162686812.

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 218686261 - 2¹⁵ = 218653493 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218686241) 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, 24745 + ... + 32398.

It is an arithmetic number, because the mean of its divisors is an integer number (28286280).

Almost surely, 2^218686261 is an apocalyptic number.

It is an amenable number.

218686261 is a deficient number, since it is larger than the sum of its proper divisors (7603979).

218686261 is an equidigital number, since it uses as much as digits as its factorization.

218686261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57275.

The product of its digits is 55296, while the sum is 40.

The square root of 218686261 is about 14788.0445292811. The cubic root of 218686261 is about 602.4770384321.

The spelling of 218686261 in words is "two hundred eighteen million, six hundred eighty-six thousand, two hundred sixty-one".