21021221112011 has 2 divisors, whose sum is σ = 21021221112012. Its totient is φ = 21021221112010.

The previous prime is 21021221111987. The next prime is 21021221112053. The reversal of 21021221112011 is 11021112212012.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21021221112011 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (21021221112611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510610556005 + 10510610556006.

It is an arithmetic number, because the mean of its divisors is an integer number (10510610556006).

Almost surely, 2^{21021221112011} is an apocalyptic number.

21021221112011 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021221112011 is an equidigital number, since it uses as much as digits as its factorization.

21021221112011 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 21021221112011 its reverse (11021112212012), we get a palindrome (32042333324023).

The spelling of 21021221112011 in words is "twenty-one trillion, twenty-one billion, two hundred twenty-one million, one hundred twelve thousand, eleven".