21201101111 has 2 divisors, whose sum is σ = 21201101112. Its totient is φ = 21201101110.

The previous prime is 21201101101. The next prime is 21201101143. The reversal of 21201101111 is 11110110212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21201101111 - 2²⁶ = 21133992247 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21201101092 and 21201101101.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21201101101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600550555 + 10600550556.

It is an arithmetic number, because the mean of its divisors is an integer number (10600550556).

Almost surely, 2^21201101111 is an apocalyptic number.

21201101111 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201101111 is an equidigital number, since it uses as much as digits as its factorization.

21201101111 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 21201101111 its reverse (11110110212), we get a palindrome (32311211323).

The spelling of 21201101111 in words is "twenty-one billion, two hundred one million, one hundred one thousand, one hundred eleven".