21333112121 has 8 divisors (see below), whose sum is σ = 21598907400. Its totient is φ = 21067896960.

The previous prime is 21333112109. The next prime is 21333112159. The reversal of 21333112121 is 12121133312.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 5959840000 + 15373272121 = 77200^2 + 123989^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21333112121 - 2²⁶ = 21266003257 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21333112093 and 21333112102.

It is not an unprimeable number, because it can be changed into a prime (21333112721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70790 + ... + 218351.

It is an arithmetic number, because the mean of its divisors is an integer number (2699863425).

Almost surely, 2^21333112121 is an apocalyptic number.

It is an amenable number.

21333112121 is a deficient number, since it is larger than the sum of its proper divisors (265795279).

21333112121 is an equidigital number, since it uses as much as digits as its factorization.

21333112121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 290059.

The product of its digits is 216, while the sum is 20.

Adding to 21333112121 its reverse (12121133312), we get a palindrome (33454245433).

The spelling of 21333112121 in words is "twenty-one billion, three hundred thirty-three million, one hundred twelve thousand, one hundred twenty-one".