21212202111911 has 2 divisors, whose sum is σ = 21212202111912. Its totient is φ = 21212202111910.

The previous prime is 21212202111853. The next prime is 21212202111913. The reversal of 21212202111911 is 11911120221212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21212202111911 - 2³⁴ = 21195022242727 is a prime.

It is a super-2 number, since 2×21212202111911² (a number of 27 digits) contains 22 as substring.

It is a Sophie Germain prime.

Together with 21212202111913, 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 (21212202111913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606101055955 + 10606101055956.

It is an arithmetic number, because the mean of its divisors is an integer number (10606101055956).

Almost surely, 2^{21212202111911} is an apocalyptic number.

21212202111911 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212202111911 is an equidigital number, since it uses as much as digits as its factorization.

21212202111911 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 26.

The spelling of 21212202111911 in words is "twenty-one trillion, two hundred twelve billion, two hundred two million, one hundred eleven thousand, nine hundred eleven".