218501 has 4 divisors (see below), whose sum is σ = 231372. Its totient is φ = 205632.

The previous prime is 218479. The next prime is 218509. The reversal of 218501 is 105812.

218501 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 112225 + 106276 = 335^2 + 326^2 .

It is not a de Polignac number, because 218501 - 2⁶ = 218437 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17), and also a Moran number because the ratio is a prime number: 12853 = 218501 / (2 + 1 + 8 + 5 + 0 + 1).

It is an alternating number because its digits alternate between even and odd.

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 218501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218509) 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, 6410 + ... + 6443.

It is an arithmetic number, because the mean of its divisors is an integer number (57843).

2²¹⁸⁵⁰¹ is an apocalyptic number.

It is an amenable number.

218501 is a deficient number, since it is larger than the sum of its proper divisors (12871).

218501 is a wasteful number, since it uses less digits than its factorization.

218501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12870.

The product of its (nonzero) digits is 80, while the sum is 17.

The square root of 218501 is about 467.4409053560. The cubic root of 218501 is about 60.2306860035.

The spelling of 218501 in words is "two hundred eighteen thousand, five hundred one".