261218 has 8 divisors (see below), whose sum is σ = 394320. Its totient is φ = 129780.

The previous prime is 261169. The next prime is 261223. The reversal of 261218 is 812162.

261218 = 142² + 143² + ... + 153².

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 261218.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 113 + ... + 731.

It is an arithmetic number, because the mean of its divisors is an integer number (49290).

2²⁶¹²¹⁸ is an apocalyptic number.

261218 is a deficient number, since it is larger than the sum of its proper divisors (133102).

261218 is a wasteful number, since it uses less digits than its factorization.

261218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 832.

The product of its digits is 192, while the sum is 20.

The square root of 261218 is about 511.0949031247. The cubic root of 261218 is about 63.9245530207.

The spelling of 261218 in words is "two hundred sixty-one thousand, two hundred eighteen".