218640711343021 has 16 divisors (see below), whose sum is σ = 251096318668800. Its totient is φ = 188283770967600.

The previous prime is 218640711342953. The next prime is 218640711343031. The reversal of 218640711343021 is 120343117046812.

It is not a de Polignac number, because 218640711343021 - 2²³ = 218640702954413 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218640711343031) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 51376611 + ... + 55469248.

It is an arithmetic number, because the mean of its divisors is an integer number (15693519916800).

Almost surely, 2^{218640711343021} is an apocalyptic number.

It is an amenable number.

218640711343021 is a deficient number, since it is larger than the sum of its proper divisors (32455607325779).

218640711343021 is a wasteful number, since it uses less digits than its factorization.

218640711343021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106855680.

The product of its (nonzero) digits is 193536, while the sum is 43.

Adding to 218640711343021 its reverse (120343117046812), we get a palindrome (338983828389833).

The spelling of 218640711343021 in words is "two hundred eighteen trillion, six hundred forty billion, seven hundred eleven million, three hundred forty-three thousand, twenty-one".