21133333121 has 2 divisors, whose sum is σ = 21133333122. Its totient is φ = 21133333120.

The previous prime is 21133333037. The next prime is 21133333157. The reversal of 21133333121 is 12133333112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21130692496 + 2640625 = 145364^2 + 1625^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21133333121 is a prime.

It is not a weakly prime, because it can be changed into another prime (21133333421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10566666560 + 10566666561.

It is an arithmetic number, because the mean of its divisors is an integer number (10566666561).

Almost surely, 2^21133333121 is an apocalyptic number.

It is an amenable number.

21133333121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21133333121 is an equidigital number, since it uses as much as digits as its factorization.

21133333121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 972, while the sum is 23.

Adding to 21133333121 its reverse (12133333112), we get a palindrome (33266666233).

Subtracting from 21133333121 its reverse (12133333112), we obtain a palindrome (9000000009).

The spelling of 21133333121 in words is "twenty-one billion, one hundred thirty-three million, three hundred thirty-three thousand, one hundred twenty-one".