21212220213133 has 4 divisors (see below), whose sum is σ = 21212307257308. Its totient is φ = 21212133168960.

The previous prime is 21212220213113. The next prime is 21212220213139. The reversal of 21212220213133 is 33131202221212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13961118385764 + 7251101827369 = 3736458^2 + 2692787^2 .

It is a cyclic number.

It is not a de Polignac number, because 21212220213133 - 2⁵ = 21212220213101 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21212220213098 and 21212220213107.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212220213139) 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, 43155516 + ... + 43644277.

It is an arithmetic number, because the mean of its divisors is an integer number (5303076814327).

Almost surely, 2^{21212220213133} is an apocalyptic number.

It is an amenable number.

21212220213133 is a deficient number, since it is larger than the sum of its proper divisors (87044175).

21212220213133 is an equidigital number, since it uses as much as digits as its factorization.

21212220213133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87044174.

The product of its (nonzero) digits is 1728, while the sum is 25.

Adding to 21212220213133 its reverse (33131202221212), we get a palindrome (54343422434345).

The spelling of 21212220213133 in words is "twenty-one trillion, two hundred twelve billion, two hundred twenty million, two hundred thirteen thousand, one hundred thirty-three".