21110031211 has 2 divisors, whose sum is σ = 21110031212. Its totient is φ = 21110031210.

The previous prime is 21110031179. The next prime is 21110031227. The reversal of 21110031211 is 11213001112.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21110031211 - 2⁵ = 21110031179 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21110031191 and 21110031200.

It is not a weakly prime, because it can be changed into another prime (21110031611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555015605 + 10555015606.

It is an arithmetic number, because the mean of its divisors is an integer number (10555015606).

Almost surely, 2^21110031211 is an apocalyptic number.

21110031211 is a deficient number, since it is larger than the sum of its proper divisors (1).

21110031211 is an equidigital number, since it uses as much as digits as its factorization.

21110031211 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12, while the sum is 13.

Adding to 21110031211 its reverse (11213001112), we get a palindrome (32323032323).

The spelling of 21110031211 in words is "twenty-one billion, one hundred ten million, thirty-one thousand, two hundred eleven".