21100223210161 has 2 divisors, whose sum is σ = 21100223210162. Its totient is φ = 21100223210160.

The previous prime is 21100223210119. The next prime is 21100223210173. The reversal of 21100223210161 is 16101232200112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15099286208400 + 6000937001761 = 3885780^2 + 2449681^2 .

It is a cyclic number.

It is not a de Polignac number, because 21100223210161 - 2¹⁹ = 21100222685873 is a prime.

It is not a weakly prime, because it can be changed into another prime (21100223213161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550111605080 + 10550111605081.

It is an arithmetic number, because the mean of its divisors is an integer number (10550111605081).

Almost surely, 2^{21100223210161} is an apocalyptic number.

It is an amenable number.

21100223210161 is a deficient number, since it is larger than the sum of its proper divisors (1).

21100223210161 is an equidigital number, since it uses as much as digits as its factorization.

21100223210161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 22.

Adding to 21100223210161 its reverse (16101232200112), we get a palindrome (37201455410273).

The spelling of 21100223210161 in words is "twenty-one trillion, one hundred billion, two hundred twenty-three million, two hundred ten thousand, one hundred sixty-one".