20218291 has 2 divisors, whose sum is σ = 20218292. Its totient is φ = 20218290.

The previous prime is 20218271. The next prime is 20218313. The reversal of 20218291 is 19281202.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20218291 - 2⁵ = 20218259 is a prime.

It is not a weakly prime, because it can be changed into another prime (20218271) by changing a digit.

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 as a sum of consecutive naturals, namely, 10109145 + 10109146.

It is an arithmetic number, because the mean of its divisors is an integer number (10109146).

Almost surely, 2^20218291 is an apocalyptic number.

20218291 is a deficient number, since it is larger than the sum of its proper divisors (1).

20218291 is an equidigital number, since it uses as much as digits as its factorization.

20218291 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 20218291 is about 4496.4753974641. The cubic root of 20218291 is about 272.4257452758.

Adding to 20218291 its reverse (19281202), we get a palindrome (39499493).

The spelling of 20218291 in words is "twenty million, two hundred eighteen thousand, two hundred ninety-one".