21011221022047 has 2 divisors, whose sum is σ = 21011221022048. Its totient is φ = 21011221022046.

The previous prime is 21011221021979. The next prime is 21011221022063. The reversal of 21011221022047 is 74022012211012.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21011221022047 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21011221022087) 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, 10505610511023 + 10505610511024.

It is an arithmetic number, because the mean of its divisors is an integer number (10505610511024).

Almost surely, 2^{21011221022047} is an apocalyptic number.

21011221022047 is a deficient number, since it is larger than the sum of its proper divisors (1).

21011221022047 is an equidigital number, since it uses as much as digits as its factorization.

21011221022047 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 21011221022047 its reverse (74022012211012), we get a palindrome (95033233233059).

The spelling of 21011221022047 in words is "twenty-one trillion, eleven billion, two hundred twenty-one million, twenty-two thousand, forty-seven".