5221806818 has 18 divisors (see below), whose sum is σ = 8055960003. Its totient is φ = 2538498960.

The previous prime is 5221806773. The next prime is 5221806839. The reversal of 5221806818 is 8186081225.

It is a happy number.

It can be written as a sum of positive squares in 5 ways, for example, as 4518125089 + 703681729 = 67217^2 + 26527^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=51097.

It is a super-2 number, since 2×5221806818² = 54534532889022570248, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3780488 + ... + 3781868.

Almost surely, 2^5221806818 is an apocalyptic number.

5221806818 is a deficient number, since it is larger than the sum of its proper divisors (2834153185).

5221806818 is an frugal number, since it uses more digits than its factorization.

5221806818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2838 (or 1420 counting only the distinct ones).

The product of its (nonzero) digits is 61440, while the sum is 41.

The square root of 5221806818 is about 72262.0703965780. The cubic root of 5221806818 is about 1734.8966176250.

The spelling of 5221806818 in words is "five billion, two hundred twenty-one million, eight hundred six thousand, eight hundred eighteen".