217133305 has 8 divisors (see below), whose sum is σ = 261127944. Its totient is φ = 173328000.

The previous prime is 217133261. The next prime is 217133309. The reversal of 217133305 is 503331712.

It can be written as a sum of positive squares in 4 ways, for example, as 37063744 + 180069561 = 6088^2 + 13419^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 217133305 - 2⁷ = 217133177 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 217133305.

It is not an unprimeable number, because it can be changed into a prime (217133309) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44796 + ... + 49405.

It is an arithmetic number, because the mean of its divisors is an integer number (32640993).

Almost surely, 2^217133305 is an apocalyptic number.

It is an amenable number.

217133305 is a deficient number, since it is larger than the sum of its proper divisors (43994639).

217133305 is an equidigital number, since it uses as much as digits as its factorization.

217133305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94667.

The product of its (nonzero) digits is 1890, while the sum is 25.

The square root of 217133305 is about 14735.4438345100. The cubic root of 217133305 is about 601.0475265640.

The spelling of 217133305 in words is "two hundred seventeen million, one hundred thirty-three thousand, three hundred five".