218340331 has 4 divisors (see below), whose sum is σ = 238189464. Its totient is φ = 198491200.

The previous prime is 218340329. The next prime is 218340379. The reversal of 218340331 is 133043812.

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 218340331 - 2¹ = 218340329 is a prime.

It is a super-2 number, since 2×218340331² = 95345000282379122, 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 = 218340296 and 218340305.

It is not an unprimeable number, because it can be changed into a prime (218340301) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9924550 + ... + 9924571.

It is an arithmetic number, because the mean of its divisors is an integer number (59547366).

Almost surely, 2^218340331 is an apocalyptic number.

218340331 is a deficient number, since it is larger than the sum of its proper divisors (19849133).

218340331 is a wasteful number, since it uses less digits than its factorization.

218340331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19849132.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 218340331 is about 14776.3436275690. The cubic root of 218340331 is about 602.1591936322.

The spelling of 218340331 in words is "two hundred eighteen million, three hundred forty thousand, three hundred thirty-one".