21211200120247 has 2 divisors, whose sum is σ = 21211200120248. Its totient is φ = 21211200120246.

The previous prime is 21211200120241. The next prime is 21211200120251. The reversal of 21211200120247 is 74202100211212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21211200120247 - 2⁷ = 21211200120119 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21211200120241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605600060123 + 10605600060124.

It is an arithmetic number, because the mean of its divisors is an integer number (10605600060124).

Almost surely, 2^{21211200120247} is an apocalyptic number.

21211200120247 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211200120247 is an equidigital number, since it uses as much as digits as its factorization.

21211200120247 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 896, while the sum is 25.

Adding to 21211200120247 its reverse (74202100211212), we get a palindrome (95413300331459).

The spelling of 21211200120247 in words is "twenty-one trillion, two hundred eleven billion, two hundred million, one hundred twenty thousand, two hundred forty-seven".