218257139 has 2 divisors, whose sum is σ = 218257140. Its totient is φ = 218257138.

The previous prime is 218257129. The next prime is 218257141. The reversal of 218257139 is 931752812.

218257139 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 218257139 - 2²⁴ = 201479923 is a prime.

Together with 218257141, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (218257129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109128569 + 109128570.

It is an arithmetic number, because the mean of its divisors is an integer number (109128570).

Almost surely, 2^218257139 is an apocalyptic number.

218257139 is a deficient number, since it is larger than the sum of its proper divisors (1).

218257139 is an equidigital number, since it uses as much as digits as its factorization.

218257139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30240, while the sum is 38.

The square root of 218257139 is about 14773.5283192608. The cubic root of 218257139 is about 602.0827057151.

The spelling of 218257139 in words is "two hundred eighteen million, two hundred fifty-seven thousand, one hundred thirty-nine".