21111221100169 has 2 divisors, whose sum is σ = 21111221100170. Its totient is φ = 21111221100168.

The previous prime is 21111221100127. The next prime is 21111221100239. The reversal of 21111221100169 is 96100112211112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15595825214025 + 5515395886144 = 3949155^2 + 2348488^2 .

It is a cyclic number.

It is not a de Polignac number, because 21111221100169 - 2¹⁵ = 21111221067401 is a prime.

It is a super-2 number, since 2×21111221100169² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21111221100569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555610550084 + 10555610550085.

It is an arithmetic number, because the mean of its divisors is an integer number (10555610550085).

Almost surely, 2^{21111221100169} is an apocalyptic number.

It is an amenable number.

21111221100169 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111221100169 is an equidigital number, since it uses as much as digits as its factorization.

21111221100169 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 28.

The spelling of 21111221100169 in words is "twenty-one trillion, one hundred eleven billion, two hundred twenty-one million, one hundred thousand, one hundred sixty-nine".