217872005 has 8 divisors (see below), whose sum is σ = 281557752. Its totient is φ = 160890048.

The previous prime is 217871989. The next prime is 217872043. The reversal of 217872005 is 500278712.

It can be written as a sum of positive squares in 4 ways, for example, as 73441 + 217798564 = 271^2 + 14758^2 .

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 217872005 - 2⁴ = 217871989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1675874 + ... + 1676003.

It is an arithmetic number, because the mean of its divisors is an integer number (35194719).

Almost surely, 2^217872005 is an apocalyptic number.

It is an amenable number.

217872005 is a deficient number, since it is larger than the sum of its proper divisors (63685747).

217872005 is a wasteful number, since it uses less digits than its factorization.

217872005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3351895.

The product of its (nonzero) digits is 7840, while the sum is 32.

The square root of 217872005 is about 14760.4879661887. The cubic root of 217872005 is about 601.7283545003.

The spelling of 217872005 in words is "two hundred seventeen million, eight hundred seventy-two thousand, five".