21112021061 has 2 divisors, whose sum is σ = 21112021062. Its totient is φ = 21112021060.

The previous prime is 21112021033. The next prime is 21112021087. The reversal of 21112021061 is 16012021112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17405524900 + 3706496161 = 131930^2 + 60881^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112021061 - 2²² = 21107826757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21112021661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556010530 + 10556010531.

It is an arithmetic number, because the mean of its divisors is an integer number (10556010531).

Almost surely, 2^21112021061 is an apocalyptic number.

It is an amenable number.

21112021061 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112021061 is an equidigital number, since it uses as much as digits as its factorization.

21112021061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48, while the sum is 17.

Adding to 21112021061 its reverse (16012021112), we get a palindrome (37124042173).

The spelling of 21112021061 in words is "twenty-one billion, one hundred twelve million, twenty-one thousand, sixty-one".