21201110212001 has 2 divisors, whose sum is σ = 21201110212002. Its totient is φ = 21201110212000.

The previous prime is 21201110211977. The next prime is 21201110212003. The reversal of 21201110212001 is 10021201110212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21054286365025 + 146823846976 = 4588495^2 + 383176^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21201110212001 is a prime.

Together with 21201110212003, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21201110212003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600555106000 + 10600555106001.

It is an arithmetic number, because the mean of its divisors is an integer number (10600555106001).

Almost surely, 2^{21201110212001} is an apocalyptic number.

It is an amenable number.

21201110212001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201110212001 is an equidigital number, since it uses as much as digits as its factorization.

21201110212001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21201110212001 its reverse (10021201110212), we get a palindrome (31222311322213).

The spelling of 21201110212001 in words is "twenty-one trillion, two hundred one billion, one hundred ten million, two hundred twelve thousand, one".