21022405205220 has 36 divisors (see below), whose sum is σ = 63767962456380. Its totient is φ = 5605974721344.

The previous prime is 21022405205213. The next prime is 21022405205231. The reversal of 21022405205220 is 2250250422012.

It is a happy number.

21022405205220 is a `hidden beast` number, since 2 + 10 + 2 + 2 + 405 + 20 + 5 + 220 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 4343822945856 + 16678582259364 = 2084184^2 + 4083942^2 .

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

It is a super-2 number, since 2×21022405205220² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 58395569835 + ... + 58395570194.

It is an arithmetic number, because the mean of its divisors is an integer number (1771332290455).

Almost surely, 2^{21022405205220} is an apocalyptic number.

21022405205220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21022405205220 is an abundant number, since it is smaller than the sum of its proper divisors (42745557251160).

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

21022405205220 is a wasteful number, since it uses less digits than its factorization.

21022405205220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116791140044 (or 116791140039 counting only the distinct ones).

The product of its (nonzero) digits is 6400, while the sum is 27.

Adding to 21022405205220 its reverse (2250250422012), we get a palindrome (23272655627232).

The spelling of 21022405205220 in words is "twenty-one trillion, twenty-two billion, four hundred five million, two hundred five thousand, two hundred twenty".