21234020111 has 2 divisors, whose sum is σ = 21234020112. Its totient is φ = 21234020110.

The previous prime is 21234020099. The next prime is 21234020131. The reversal of 21234020111 is 11102043212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21234020111 - 2¹⁰ = 21234019087 is a prime.

It is a super-2 number, since 2×21234020111² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21234020111.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21234020131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10617010055 + 10617010056.

It is an arithmetic number, because the mean of its divisors is an integer number (10617010056).

Almost surely, 2^21234020111 is an apocalyptic number.

21234020111 is a deficient number, since it is larger than the sum of its proper divisors (1).

21234020111 is an equidigital number, since it uses as much as digits as its factorization.

21234020111 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 21234020111 its reverse (11102043212), we get a palindrome (32336063323).

The spelling of 21234020111 in words is "twenty-one billion, two hundred thirty-four million, twenty thousand, one hundred eleven".