21110100111161 has 2 divisors, whose sum is σ = 21110100111162. Its totient is φ = 21110100111160.

The previous prime is 21110100111127. The next prime is 21110100111299. The reversal of 21110100111161 is 16111100101112.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16822794433600 + 4287305677561 = 4101560^2 + 2070581^2 .

It is a cyclic number.

It is not a de Polignac number, because 21110100111161 - 2⁶ = 21110100111097 is a prime.

It is not a weakly prime, because it can be changed into another prime (21110100111461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555050055580 + 10555050055581.

It is an arithmetic number, because the mean of its divisors is an integer number (10555050055581).

Almost surely, 2^{21110100111161} is an apocalyptic number.

It is an amenable number.

21110100111161 is a deficient number, since it is larger than the sum of its proper divisors (1).

21110100111161 is an equidigital number, since it uses as much as digits as its factorization.

21110100111161 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 17.

Adding to 21110100111161 its reverse (16111100101112), we get a palindrome (37221200212273).

The spelling of 21110100111161 in words is "twenty-one trillion, one hundred ten billion, one hundred million, one hundred eleven thousand, one hundred sixty-one".