105215321 has 2 divisors, whose sum is σ = 105215322. Its totient is φ = 105215320.

The previous prime is 105215291. The next prime is 105215323. The reversal of 105215321 is 123512501.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 104142025 + 1073296 = 10205^2 + 1036^2 .

It is a cyclic number.

It is not a de Polignac number, because 105215321 - 2¹⁴ = 105198937 is a prime.

It is a super-2 number, since 2×105215321² = 22140527546266082, which contains 22 as substring.

Together with 105215323, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_6044411 and since 105215321 and 6044411 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 105215293 and 105215302.

It is not a weakly prime, because it can be changed into another prime (105215323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 52607660 + 52607661.

It is an arithmetic number, because the mean of its divisors is an integer number (52607661).

Almost surely, 2^105215321 is an apocalyptic number.

It is an amenable number.

105215321 is a deficient number, since it is larger than the sum of its proper divisors (1).

105215321 is an equidigital number, since it uses as much as digits as its factorization.

105215321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 300, while the sum is 20.

The square root of 105215321 is about 10257.4519740528. The cubic root of 105215321 is about 472.0916599376.

Adding to 105215321 its reverse (123512501), we get a palindrome (228727822).

The spelling of 105215321 in words is "one hundred five million, two hundred fifteen thousand, three hundred twenty-one".