218651 has 2 divisors, whose sum is σ = 218652. Its totient is φ = 218650.

The previous prime is 218641. The next prime is 218657. The reversal of 218651 is 156812.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-218651 is a prime.

It is a Chen prime.

It is a plaindrome in base 15.

It is a zygodrome in base 15.

It is not a weakly prime, because it can be changed into another prime (218657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109325 + 109326.

It is an arithmetic number, because the mean of its divisors is an integer number (109326).

2²¹⁸⁶⁵¹ is an apocalyptic number.

218651 is a deficient number, since it is larger than the sum of its proper divisors (1).

218651 is an equidigital number, since it uses as much as digits as its factorization.

218651 is an evil number, because the sum of its binary digits is even.

The product of its digits is 480, while the sum is 23.

The square root of 218651 is about 467.6013259177. The cubic root of 218651 is about 60.2444655534.

The spelling of 218651 in words is "two hundred eighteen thousand, six hundred fifty-one".