21421123111 has 2 divisors, whose sum is σ = 21421123112. Its totient is φ = 21421123110.

The previous prime is 21421123099. The next prime is 21421123187. The reversal of 21421123111 is 11132112412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21421123111 - 2⁹ = 21421122599 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21421153111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10710561555 + 10710561556.

It is an arithmetic number, because the mean of its divisors is an integer number (10710561556).

Almost surely, 2^21421123111 is an apocalyptic number.

21421123111 is a deficient number, since it is larger than the sum of its proper divisors (1).

21421123111 is an equidigital number, since it uses as much as digits as its factorization.

21421123111 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96, while the sum is 19.

Adding to 21421123111 its reverse (11132112412), we get a palindrome (32553235523).

The spelling of 21421123111 in words is "twenty-one billion, four hundred twenty-one million, one hundred twenty-three thousand, one hundred eleven".