218998728729 has 135 divisors (see below), whose sum is σ = 374716541199. Its totient is φ = 127363531680.

The previous prime is 218998728719. The next prime is 218998728749. The reversal of 218998728729 is 927827899812.

The square root of 218998728729 is 467973.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 114837621129 + 104161107600 = 338877^2 + 322740^2 .

It is not a de Polignac number, because 218998728729 - 2⁹ = 218998728217 is a prime.

It is not an unprimeable number, because it can be changed into a prime (218998728719) by changing a digit.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 1343550402 + ... + 1343550564.

Almost surely, 2^218998728729 is an apocalyptic number.

218998728729 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

218998728729 is the 467973-rd square number.

218998728729 is the 233987-th centered octagonal number.

It is an amenable number.

218998728729 is a deficient number, since it is larger than the sum of its proper divisors (155717812470).

218998728729 is an equidigital number, since it uses as much as digits as its factorization.

218998728729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 418 (or 206 counting only the distinct ones).

The product of its digits is 146313216, while the sum is 72.

The spelling of 218998728729 in words is "two hundred eighteen billion, nine hundred ninety-eight million, seven hundred twenty-eight thousand, seven hundred twenty-nine".