21111120361 has 2 divisors, whose sum is σ = 21111120362. Its totient is φ = 21111120360.

The previous prime is 21111120307. The next prime is 21111120391. The reversal of 21111120361 is 16302111112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19243238400 + 1867881961 = 138720^2 + 43219^2 .

It is a cyclic number.

It is not a de Polignac number, because 21111120361 - 2²³ = 21102731753 is a prime.

It is not a weakly prime, because it can be changed into another prime (21111120391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555560180 + 10555560181.

It is an arithmetic number, because the mean of its divisors is an integer number (10555560181).

Almost surely, 2^21111120361 is an apocalyptic number.

It is an amenable number.

21111120361 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111120361 is an equidigital number, since it uses as much as digits as its factorization.

21111120361 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 19.

Adding to 21111120361 its reverse (16302111112), we get a palindrome (37413231473).

The spelling of 21111120361 in words is "twenty-one billion, one hundred eleven million, one hundred twenty thousand, three hundred sixty-one".