21110011231 has 2 divisors, whose sum is σ = 21110011232. Its totient is φ = 21110011230.

The previous prime is 21110011217. The next prime is 21110011253. The reversal of 21110011231 is 13211001112.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21110011231 is a prime.

It is a super-2 number, since 2×21110011231² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21110011211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555005615 + 10555005616.

It is an arithmetic number, because the mean of its divisors is an integer number (10555005616).

Almost surely, 2^21110011231 is an apocalyptic number.

21110011231 is a deficient number, since it is larger than the sum of its proper divisors (1).

21110011231 is an equidigital number, since it uses as much as digits as its factorization.

21110011231 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 21110011231 its reverse (13211001112), we get a palindrome (34321012343).

The spelling of 21110011231 in words is "twenty-one billion, one hundred ten million, eleven thousand, two hundred thirty-one".