217172485 has 8 divisors (see below), whose sum is σ = 261122040. Its totient is φ = 173394624.

The previous prime is 217172471. The next prime is 217172491. The reversal of 217172485 is 584271712.

It can be written as a sum of positive squares in 4 ways, for example, as 32239684 + 184932801 = 5678^2 + 13599^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 217172485 - 2⁷ = 217172357 is a prime.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 40122 + ... + 45211.

It is an arithmetic number, because the mean of its divisors is an integer number (32640255).

Almost surely, 2^217172485 is an apocalyptic number.

It is an amenable number.

217172485 is a deficient number, since it is larger than the sum of its proper divisors (43949555).

217172485 is an equidigital number, since it uses as much as digits as its factorization.

217172485 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85847.

The product of its digits is 31360, while the sum is 37.

The square root of 217172485 is about 14736.7732221134. The cubic root of 217172485 is about 601.0836758254.

The spelling of 217172485 in words is "two hundred seventeen million, one hundred seventy-two thousand, four hundred eighty-five".