218313421 has 8 divisors (see below), whose sum is σ = 226621080. Its totient is φ = 210057792.

The previous prime is 218313379. The next prime is 218313463. The reversal of 218313421 is 124313812.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (218313379) and next prime (218313463).

It can be written as a sum of positive squares in 4 ways, for example, as 134792100 + 83521321 = 11610^2 + 9139^2 .

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 218313421 - 2²⁵ = 184758989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218313521) 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, 4350 + ... + 21343.

It is an arithmetic number, because the mean of its divisors is an integer number (28327635).

Almost surely, 2^218313421 is an apocalyptic number.

It is an amenable number.

218313421 is a deficient number, since it is larger than the sum of its proper divisors (8307659).

218313421 is a wasteful number, since it uses less digits than its factorization.

218313421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26015.

The product of its digits is 1152, while the sum is 25.

The square root of 218313421 is about 14775.4330224193. The cubic root of 218313421 is about 602.1344543187.

It can be divided in two parts, 21831 and 3421, that added together give a palindrome (25252).

The spelling of 218313421 in words is "two hundred eighteen million, three hundred thirteen thousand, four hundred twenty-one".