218138120020 has 12 divisors (see below), whose sum is σ = 458090052084. Its totient is φ = 87255248000.

The previous prime is 218138120017. The next prime is 218138120029. The reversal of 218138120020 is 20021831812.

218138120020 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 24330384324 + 193807735696 = 155982^2 + 440236^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218138120029) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5453452981 + ... + 5453453020.

It is an arithmetic number, because the mean of its divisors is an integer number (38174171007).

Almost surely, 2^218138120020 is an apocalyptic number.

218138120020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

218138120020 is an abundant number, since it is smaller than the sum of its proper divisors (239951932064).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

218138120020 is a wasteful number, since it uses less digits than its factorization.

218138120020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10906906010 (or 10906906008 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 28.

Adding to 218138120020 its reverse (20021831812), we get a palindrome (238159951832).

The spelling of 218138120020 in words is "two hundred eighteen billion, one hundred thirty-eight million, one hundred twenty thousand, twenty".