218870729 has 12 divisors (see below), whose sum is σ = 274946112. Its totient is φ = 170547960.

The previous prime is 218870723. The next prime is 218870753. The reversal of 218870729 is 927078812.

It is not a de Polignac number, because 218870729 - 2⁴ = 218870713 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 218870729.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218870723) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 128357 + ... + 130050.

It is an arithmetic number, because the mean of its divisors is an integer number (22912176).

Almost surely, 2^218870729 is an apocalyptic number.

It is an amenable number.

218870729 is a deficient number, since it is larger than the sum of its proper divisors (56075383).

218870729 is a wasteful number, since it uses less digits than its factorization.

218870729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 258436 (or 258425 counting only the distinct ones).

The product of its (nonzero) digits is 112896, while the sum is 44.

The square root of 218870729 is about 14794.2802798920. The cubic root of 218870729 is about 602.6463929207.

The spelling of 218870729 in words is "two hundred eighteen million, eight hundred seventy thousand, seven hundred twenty-nine".