21111034481 has 2 divisors, whose sum is σ = 21111034482. Its totient is φ = 21111034480.

The previous prime is 21111034453. The next prime is 21111034531. The reversal of 21111034481 is 18443011112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20446426081 + 664608400 = 142991^2 + 25780^2 .

It is a cyclic number.

It is not a de Polignac number, because 21111034481 - 2³⁴ = 3931165297 is a prime.

It is a super-2 number, since 2×21111034481² (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 21111034481.

It is not a weakly prime, because it can be changed into another prime (21111034381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555517240 + 10555517241.

It is an arithmetic number, because the mean of its divisors is an integer number (10555517241).

Almost surely, 2^21111034481 is an apocalyptic number.

It is an amenable number.

21111034481 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111034481 is an equidigital number, since it uses as much as digits as its factorization.

21111034481 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 768, while the sum is 26.

Adding to 21111034481 its reverse (18443011112), we get a palindrome (39554045593).

The spelling of 21111034481 in words is "twenty-one billion, one hundred eleven million, thirty-four thousand, four hundred eighty-one".