21021201121 has 2 divisors, whose sum is σ = 21021201122. Its totient is φ = 21021201120.

The previous prime is 21021201079. The next prime is 21021201151. The reversal of 21021201121 is 12110212012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16709440225 + 4311760896 = 129265^2 + 65664^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21021201121 is a prime.

It is not a weakly prime, because it can be changed into another prime (21021201151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510600560 + 10510600561.

It is an arithmetic number, because the mean of its divisors is an integer number (10510600561).

Almost surely, 2^21021201121 is an apocalyptic number.

It is an amenable number.

21021201121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021201121 is an equidigital number, since it uses as much as digits as its factorization.

21021201121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21021201121 its reverse (12110212012), we get a palindrome (33131413133).

The spelling of 21021201121 in words is "twenty-one billion, twenty-one million, two hundred one thousand, one hundred twenty-one".