21000201121 has 2 divisors, whose sum is σ = 21000201122. Its totient is φ = 21000201120.

The previous prime is 21000201113. The next prime is 21000201137. The reversal of 21000201121 is 12110200012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12593328400 + 8406872721 = 112220^2 + 91689^2 .

It is a cyclic number.

It is not a de Polignac number, because 21000201121 - 2³ = 21000201113 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21000201098 and 21000201107.

It is not a weakly prime, because it can be changed into another prime (21000201161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500100560 + 10500100561.

It is an arithmetic number, because the mean of its divisors is an integer number (10500100561).

Almost surely, 2^21000201121 is an apocalyptic number.

It is an amenable number.

21000201121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000201121 is an equidigital number, since it uses as much as digits as its factorization.

21000201121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21000201121 its reverse (12110200012), we get a palindrome (33110401133).

The spelling of 21000201121 in words is "twenty-one billion, two hundred one thousand, one hundred twenty-one".