2217891985 has 8 divisors (see below), whose sum is σ = 2705101416. Its totient is φ = 1745226240.

The previous prime is 2217891979. The next prime is 2217892003. The reversal of 2217891985 is 5891987122.

It can be written as a sum of positive squares in 4 ways, for example, as 112275216 + 2105616769 = 10596^2 + 45887^2 .

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

It is not a de Polignac number, because 2217891985 - 2⁵ = 2217891953 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3635584 + ... + 3636193.

It is an arithmetic number, because the mean of its divisors is an integer number (338137677).

Almost surely, 2^2217891985 is an apocalyptic number.

It is an amenable number.

2217891985 is a deficient number, since it is larger than the sum of its proper divisors (487209431).

2217891985 is an equidigital number, since it uses as much as digits as its factorization.

2217891985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7271843.

The product of its digits is 725760, while the sum is 52.

The square root of 2217891985 is about 47094.5005812781. The cubic root of 2217891985 is about 1304.1077139576.

The spelling of 2217891985 in words is "two billion, two hundred seventeen million, eight hundred ninety-one thousand, nine hundred eighty-five".