218251231 has 8 divisors (see below), whose sum is σ = 241446528. Its totient is φ = 195615000.

The previous prime is 218251223. The next prime is 218251249. The reversal of 218251231 is 132152812.

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 218251231 - 2³ = 218251223 is a prime.

It is a super-2 number, since 2×218251231² = 95267199666030722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 218251196 and 218251205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218251291) 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 7 ways as a sum of consecutive naturals, for example, 138945 + ... + 140506.

It is an arithmetic number, because the mean of its divisors is an integer number (30180816).

Almost surely, 2^218251231 is an apocalyptic number.

218251231 is a deficient number, since it is larger than the sum of its proper divisors (23195297).

218251231 is a wasteful number, since it uses less digits than its factorization.

218251231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 279533.

The product of its digits is 960, while the sum is 25.

The square root of 218251231 is about 14773.3283656731. The cubic root of 218251231 is about 602.0772730762.

The spelling of 218251231 in words is "two hundred eighteen million, two hundred fifty-one thousand, two hundred thirty-one".