210211212721 has 2 divisors, whose sum is σ = 210211212722. Its totient is φ = 210211212720.

The previous prime is 210211212719. The next prime is 210211212811. The reversal of 210211212721 is 127212112012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 173438931600 + 36772281121 = 416460^2 + 191761^2 .

It is a cyclic number.

It is not a de Polignac number, because 210211212721 - 2¹ = 210211212719 is a prime.

Together with 210211212719, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 210211212692 and 210211212701.

It is not a weakly prime, because it can be changed into another prime (210211212121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105105606360 + 105105606361.

It is an arithmetic number, because the mean of its divisors is an integer number (105105606361).

Almost surely, 2^210211212721 is an apocalyptic number.

It is an amenable number.

210211212721 is a deficient number, since it is larger than the sum of its proper divisors (1).

210211212721 is an equidigital number, since it uses as much as digits as its factorization.

210211212721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 224, while the sum is 22.

Adding to 210211212721 its reverse (127212112012), we get a palindrome (337423324733).

The spelling of 210211212721 in words is "two hundred ten billion, two hundred eleven million, two hundred twelve thousand, seven hundred twenty-one".