201011211101821 has 2 divisors, whose sum is σ = 201011211101822. Its totient is φ = 201011211101820.

The previous prime is 201011211101819. The next prime is 201011211101867. The reversal of 201011211101821 is 128101112110102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 132468360060100 + 68542851041721 = 11509490^2 + 8279061^2 .

It is a cyclic number.

It is not a de Polignac number, because 201011211101821 - 2¹ = 201011211101819 is a prime.

Together with 201011211101819, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 201011211101792 and 201011211101801.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201011211101801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100505605550910 + 100505605550911.

It is an arithmetic number, because the mean of its divisors is an integer number (100505605550911).

Almost surely, 2^{201011211101821} is an apocalyptic number.

It is an amenable number.

201011211101821 is a deficient number, since it is larger than the sum of its proper divisors (1).

201011211101821 is an equidigital number, since it uses as much as digits as its factorization.

201011211101821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 22.

Adding to 201011211101821 its reverse (128101112110102), we get a palindrome (329112323211923).

The spelling of 201011211101821 in words is "two hundred one trillion, eleven billion, two hundred eleven million, one hundred one thousand, eight hundred twenty-one".