218321721018496 has 16 divisors (see below), whose sum is σ = 434937803591790. Its totient is φ = 109160860509184.

The previous prime is 218321721018451. The next prime is 218321721018517. The reversal of 218321721018496 is 694810127123812.

It can be written as a sum of positive squares in only one way, i.e., 209775827649600 + 8545893368896 = 14483640^2 + 2923336^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is a super-3 number, since 3×218321721018496³ (a number of 44 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 852819222601 + ... + 852819222856.

Almost surely, 2^{218321721018496} is an apocalyptic number.

It is an amenable number.

218321721018496 is a deficient number, since it is larger than the sum of its proper divisors (216616082573294).

218321721018496 is an equidigital number, since it uses as much as digits as its factorization.

218321721018496 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1705638445471 (or 1705638445459 counting only the distinct ones).

The product of its (nonzero) digits is 2322432, while the sum is 55.

The spelling of 218321721018496 in words is "two hundred eighteen trillion, three hundred twenty-one billion, seven hundred twenty-one million, eighteen thousand, four hundred ninety-six".