21210111010001 has 2 divisors, whose sum is σ = 21210111010002. Its totient is φ = 21210111010000.

The previous prime is 21210111009979. The next prime is 21210111010007. The reversal of 21210111010001 is 10001011101212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15650885454400 + 5559225555601 = 3956120^2 + 2357801^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21210111010001 is a prime.

It is not a weakly prime, because it can be changed into another prime (21210111010007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605055505000 + 10605055505001.

It is an arithmetic number, because the mean of its divisors is an integer number (10605055505001).

Almost surely, 2^{21210111010001} is an apocalyptic number.

It is an amenable number.

21210111010001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210111010001 is an equidigital number, since it uses as much as digits as its factorization.

21210111010001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 21210111010001 its reverse (10001011101212), we get a palindrome (31211122111213).

The spelling of 21210111010001 in words is "twenty-one trillion, two hundred ten billion, one hundred eleven million, ten thousand, one".