21211221210169 has 2 divisors, whose sum is σ = 21211221210170. Its totient is φ = 21211221210168.

The previous prime is 21211221210031. The next prime is 21211221210181. The reversal of 21211221210169 is 96101212211212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16207105898025 + 5004115312144 = 4025805^2 + 2236988^2 .

It is a cyclic number.

It is not a de Polignac number, because 21211221210169 - 2¹⁵ = 21211221177401 is a prime.

It is a super-2 number, since 2×21211221210169² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21211221210169.

It is not a weakly prime, because it can be changed into another prime (21211221219169) 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, 10605610605084 + 10605610605085.

It is an arithmetic number, because the mean of its divisors is an integer number (10605610605085).

Almost surely, 2^{21211221210169} is an apocalyptic number.

It is an amenable number.

21211221210169 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211221210169 is an equidigital number, since it uses as much as digits as its factorization.

21211221210169 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 31.

The spelling of 21211221210169 in words is "twenty-one trillion, two hundred eleven billion, two hundred twenty-one million, two hundred ten thousand, one hundred sixty-nine".