217258081 has 4 divisors (see below), whose sum is σ = 217294000. Its totient is φ = 217222164.

The previous prime is 217258039. The next prime is 217258109. The reversal of 217258081 is 180852712.

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 a de Polignac number, because none of the positive numbers 2^k-217258081 is a prime.

It is a super-2 number, since 2×217258081² = 94402147519605122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (217258031) 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, 6411 + ... + 21808.

It is an arithmetic number, because the mean of its divisors is an integer number (54323500).

Almost surely, 2^217258081 is an apocalyptic number.

It is an amenable number.

217258081 is a deficient number, since it is larger than the sum of its proper divisors (35919).

217258081 is an equidigital number, since it uses as much as digits as its factorization.

217258081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35918.

The product of its (nonzero) digits is 8960, while the sum is 34.

The square root of 217258081 is about 14739.6770995840. The cubic root of 217258081 is about 601.1626354909.

The spelling of 217258081 in words is "two hundred seventeen million, two hundred fifty-eight thousand, eighty-one".