5518720217 has 4 divisors (see below), whose sum is σ = 5843350836. Its totient is φ = 5194089600.

The previous prime is 5518720187. The next prime is 5518720219. The reversal of 5518720217 is 7120278155.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7120278155 = 5 ⋅1424055631.

It can be written as a sum of positive squares in 2 ways, for example, as 4191138121 + 1327582096 = 64739^2 + 36436^2 .

It is a cyclic number.

It is not a de Polignac number, because 5518720217 - 2¹² = 5518716121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (5518720219) 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, 162315284 + ... + 162315317.

It is an arithmetic number, because the mean of its divisors is an integer number (1460837709).

Almost surely, 2^5518720217 is an apocalyptic number.

It is an amenable number.

5518720217 is a deficient number, since it is larger than the sum of its proper divisors (324630619).

5518720217 is a wasteful number, since it uses less digits than its factorization.

5518720217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 324630618.

The product of its (nonzero) digits is 39200, while the sum is 38.

The square root of 5518720217 is about 74288.0893346975. The cubic root of 5518720217 is about 1767.1745933198.

The spelling of 5518720217 in words is "five billion, five hundred eighteen million, seven hundred twenty thousand, two hundred seventeen".