218056231 has 4 divisors (see below), whose sum is σ = 219500464. Its totient is φ = 216612000.

The previous prime is 218056211. The next prime is 218056243. The reversal of 218056231 is 132650812.

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

It is a cyclic number.

It is not a de Polignac number, because 218056231 - 2¹⁹ = 217531943 is a prime.

It is a super-2 number, since 2×218056231² = 95097039755850722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 218056231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218056211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 721890 + ... + 722191.

It is an arithmetic number, because the mean of its divisors is an integer number (54875116).

Almost surely, 2^218056231 is an apocalyptic number.

218056231 is a deficient number, since it is larger than the sum of its proper divisors (1444233).

218056231 is a wasteful number, since it uses less digits than its factorization.

218056231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1444232.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 218056231 is about 14766.7271593945. The cubic root of 218056231 is about 601.8979078390.

The spelling of 218056231 in words is "two hundred eighteen million, fifty-six thousand, two hundred thirty-one".