2216491685 has 4 divisors (see below), whose sum is σ = 2659790028. Its totient is φ = 1773193344.

The previous prime is 2216491681. The next prime is 2216491691. The reversal of 2216491685 is 5861946122.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1444152004 + 772339681 = 38002^2 + 27791^2 .

It is a cyclic number.

It is not a de Polignac number, because 2216491685 - 2² = 2216491681 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2216491681) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 221649164 + ... + 221649173.

It is an arithmetic number, because the mean of its divisors is an integer number (664947507).

Almost surely, 2^2216491685 is an apocalyptic number.

It is an amenable number.

2216491685 is a deficient number, since it is larger than the sum of its proper divisors (443298343).

2216491685 is an equidigital number, since it uses as much as digits as its factorization.

2216491685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 443298342.

The product of its digits is 207360, while the sum is 44.

The square root of 2216491685 is about 47079.6313175879. The cubic root of 2216491685 is about 1303.8332000648.

The spelling of 2216491685 in words is "two billion, two hundred sixteen million, four hundred ninety-one thousand, six hundred eighty-five".