21203101121 has 2 divisors, whose sum is σ = 21203101122. Its totient is φ = 21203101120.

The previous prime is 21203101109. The next prime is 21203101159. The reversal of 21203101121 is 12110130212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21019200400 + 183900721 = 144980^2 + 13561^2 .

It is a cyclic number.

It is not a de Polignac number, because 21203101121 - 2³⁴ = 4023231937 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21203101096 and 21203101105.

It is not a weakly prime, because it can be changed into another prime (21203101021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601550560 + 10601550561.

It is an arithmetic number, because the mean of its divisors is an integer number (10601550561).

Almost surely, 2^21203101121 is an apocalyptic number.

It is an amenable number.

21203101121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21203101121 is an equidigital number, since it uses as much as digits as its factorization.

21203101121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 21203101121 its reverse (12110130212), we get a palindrome (33313231333).

The spelling of 21203101121 in words is "twenty-one billion, two hundred three million, one hundred one thousand, one hundred twenty-one".