21353331121 has 2 divisors, whose sum is σ = 21353331122. Its totient is φ = 21353331120.

The previous prime is 21353331113. The next prime is 21353331137. The reversal of 21353331121 is 12113335312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13313698225 + 8039632896 = 115385^2 + 89664^2 .

It is a cyclic number.

It is not a de Polignac number, because 21353331121 - 2³ = 21353331113 is a prime.

It is not a weakly prime, because it can be changed into another prime (21353335121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10676665560 + 10676665561.

It is an arithmetic number, because the mean of its divisors is an integer number (10676665561).

Almost surely, 2^21353331121 is an apocalyptic number.

It is an amenable number.

21353331121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21353331121 is an equidigital number, since it uses as much as digits as its factorization.

21353331121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1620, while the sum is 25.

Adding to 21353331121 its reverse (12113335312), we get a palindrome (33466666433).

The spelling of 21353331121 in words is "twenty-one billion, three hundred fifty-three million, three hundred thirty-one thousand, one hundred twenty-one".