21201220002169 has 2 divisors, whose sum is σ = 21201220002170. Its totient is φ = 21201220002168.

The previous prime is 21201220001953. The next prime is 21201220002197. The reversal of 21201220002169 is 96120002210212.

It is an a-pointer prime, because the next prime (21201220002197) can be obtained adding 21201220002169 to its sum of digits (28).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16515185676544 + 4686034325625 = 4063888^2 + 2164725^2 .

It is a cyclic number.

It is not a de Polignac number, because 21201220002169 - 2⁹ = 21201220001657 is a prime.

It is a super-2 number, since 2×21201220002169² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21201220005169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600610001084 + 10600610001085.

It is an arithmetic number, because the mean of its divisors is an integer number (10600610001085).

Almost surely, 2^{21201220002169} is an apocalyptic number.

It is an amenable number.

21201220002169 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201220002169 is an equidigital number, since it uses as much as digits as its factorization.

21201220002169 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 28.

The spelling of 21201220002169 in words is "twenty-one trillion, two hundred one billion, two hundred twenty million, two thousand, one hundred sixty-nine".