210105217 has 4 divisors (see below), whose sum is σ = 240120256. Its totient is φ = 180090180.

The previous prime is 210105209. The next prime is 210105221. The reversal of 210105217 is 712501012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 210105217 - 2³ = 210105209 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 210105194 and 210105203.

It is not an unprimeable number, because it can be changed into a prime (210105257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15007509 + ... + 15007522.

It is an arithmetic number, because the mean of its divisors is an integer number (60030064).

Almost surely, 2^210105217 is an apocalyptic number.

It is an amenable number.

210105217 is a deficient number, since it is larger than the sum of its proper divisors (30015039).

210105217 is an equidigital number, since it uses as much as digits as its factorization.

210105217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30015038.

The product of its (nonzero) digits is 140, while the sum is 19.

The square root of 210105217 is about 14495.0066229719. The cubic root of 210105217 is about 594.4914488027.

Adding to 210105217 its reverse (712501012), we get a palindrome (922606229).

The spelling of 210105217 in words is "two hundred ten million, one hundred five thousand, two hundred seventeen".