20218005 has 20 divisors (see below), whose sum is σ = 36243372. Its totient is φ = 10782720.

The previous prime is 20217949. The next prime is 20218013. The reversal of 20218005 is 50081202.

It can be written as a sum of positive squares in 2 ways, for example, as 13024881 + 7193124 = 3609^2 + 2682^2 .

It is not a de Polignac number, because 20218005 - 2⁶ = 20217941 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 24556 + ... + 25365.

Almost surely, 2^20218005 is an apocalyptic number.

It is an amenable number.

20218005 is a deficient number, since it is larger than the sum of its proper divisors (16025367).

20218005 is an equidigital number, since it uses as much as digits as its factorization.

20218005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49938 (or 49929 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 20218005 is about 4496.4435946646. The cubic root of 20218005 is about 272.4244607272.

Adding to 20218005 its reverse (50081202), we get a palindrome (70299207).

The spelling of 20218005 in words is "twenty million, two hundred eighteen thousand, five".