21121010211911 has 2 divisors, whose sum is σ = 21121010211912. Its totient is φ = 21121010211910.

The previous prime is 21121010211907. The next prime is 21121010211913. The reversal of 21121010211911 is 11911201012112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21121010211911 - 2² = 21121010211907 is a prime.

Together with 21121010211913, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21121010211913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560505105955 + 10560505105956.

It is an arithmetic number, because the mean of its divisors is an integer number (10560505105956).

Almost surely, 2^{21121010211911} is an apocalyptic number.

21121010211911 is a deficient number, since it is larger than the sum of its proper divisors (1).

21121010211911 is an equidigital number, since it uses as much as digits as its factorization.

21121010211911 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 23.

The spelling of 21121010211911 in words is "twenty-one trillion, one hundred twenty-one billion, ten million, two hundred eleven thousand, nine hundred eleven".