21213120011220 has 36 divisors (see below), whose sum is σ = 64346464034580. Its totient is φ = 5656832002944.

The previous prime is 21213120011201. The next prime is 21213120011221. The reversal of 21213120011220 is 2211002131212.

21213120011220 is a `hidden beast` number, since 2 + 121 + 312 + 0 + 0 + 11 + 220 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 13902174587844 + 7310945423376 = 3728562^2 + 2703876^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×21213120011220² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21213120011193 and 21213120011202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213120011221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 58925333185 + ... + 58925333544.

Almost surely, 2^{21213120011220} is an apocalyptic number.

21213120011220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21213120011220 is an abundant number, since it is smaller than the sum of its proper divisors (43133344023360).

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

21213120011220 is a wasteful number, since it uses less digits than its factorization.

21213120011220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117850666744 (or 117850666739 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 21213120011220 its reverse (2211002131212), we get a palindrome (23424122142432).

The spelling of 21213120011220 in words is "twenty-one trillion, two hundred thirteen billion, one hundred twenty million, eleven thousand, two hundred twenty".