21213313169 has 2 divisors, whose sum is σ = 21213313170. Its totient is φ = 21213313168.

The previous prime is 21213313159. The next prime is 21213313171. The reversal of 21213313169 is 96131331212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19572010000 + 1641303169 = 139900^2 + 40513^2 .

It is a cyclic number.

It is not a de Polignac number, because 21213313169 - 2²⁴ = 21196535953 is a prime.

It is a super-2 number, since 2×21213313169² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

Together with 21213313171, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21213313139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606656584 + 10606656585.

It is an arithmetic number, because the mean of its divisors is an integer number (10606656585).

Almost surely, 2^21213313169 is an apocalyptic number.

It is an amenable number.

21213313169 is a deficient number, since it is larger than the sum of its proper divisors (1).

21213313169 is an equidigital number, since it uses as much as digits as its factorization.

21213313169 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5832, while the sum is 32.

The spelling of 21213313169 in words is "twenty-one billion, two hundred thirteen million, three hundred thirteen thousand, one hundred sixty-nine".