218256281 has 8 divisors (see below), whose sum is σ = 223248960. Its totient is φ = 213306832.

The previous prime is 218256277. The next prime is 218256289. The reversal of 218256281 is 182652812.

It is a happy number.

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 218256281 - 2² = 218256277 is a prime.

It is a super-2 number, since 2×218256281² = 95271608391901922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (218256289) 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, 485 + ... + 20898.

It is an arithmetic number, because the mean of its divisors is an integer number (27906120).

Almost surely, 2^218256281 is an apocalyptic number.

It is an amenable number.

218256281 is a deficient number, since it is larger than the sum of its proper divisors (4992679).

218256281 is a wasteful number, since it uses less digits than its factorization.

218256281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21615.

The product of its digits is 15360, while the sum is 35.

The square root of 218256281 is about 14773.4992808068. The cubic root of 218256281 is about 602.0819167564.

The spelling of 218256281 in words is "two hundred eighteen million, two hundred fifty-six thousand, two hundred eighty-one".