218481386 has 4 divisors (see below), whose sum is σ = 327722082. Its totient is φ = 109240692.

The previous prime is 218481353. The next prime is 218481391. The reversal of 218481386 is 683184812.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 202521361 + 15960025 = 14231^2 + 3995^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 54620345 + ... + 54620348.

Almost surely, 2^218481386 is an apocalyptic number.

218481386 is a deficient number, since it is larger than the sum of its proper divisors (109240696).

218481386 is a wasteful number, since it uses less digits than its factorization.

218481386 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109240695.

The product of its digits is 73728, while the sum is 41.

The square root of 218481386 is about 14781.1158577423. The cubic root of 218481386 is about 602.2888372340.

The spelling of 218481386 in words is "two hundred eighteen million, four hundred eighty-one thousand, three hundred eighty-six".