21434021111 has 2 divisors, whose sum is σ = 21434021112. Its totient is φ = 21434021110.

The previous prime is 21434021051. The next prime is 21434021113. The reversal of 21434021111 is 11112043412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21434021111 - 2²² = 21429826807 is a prime.

Together with 21434021113, 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 (21434021113) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10717010555 + 10717010556.

It is an arithmetic number, because the mean of its divisors is an integer number (10717010556).

Almost surely, 2^21434021111 is an apocalyptic number.

21434021111 is a deficient number, since it is larger than the sum of its proper divisors (1).

21434021111 is an equidigital number, since it uses as much as digits as its factorization.

21434021111 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 20.

Adding to 21434021111 its reverse (11112043412), we get a palindrome (32546064523).

The spelling of 21434021111 in words is "twenty-one billion, four hundred thirty-four million, twenty-one thousand, one hundred eleven".