20218313 has 2 divisors, whose sum is σ = 20218314. Its totient is φ = 20218312.

The previous prime is 20218291. The next prime is 20218333. The reversal of 20218313 is 31381202.

It is an a-pointer prime, because the next prime (20218333) can be obtained adding 20218313 to its sum of digits (20).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16024009 + 4194304 = 4003^2 + 2048^2 .

It is a cyclic number.

It is not a de Polignac number, because 20218313 - 2¹⁰ = 20217289 is a prime.

It is not a weakly prime, because it can be changed into another prime (20218333) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10109156 + 10109157.

It is an arithmetic number, because the mean of its divisors is an integer number (10109157).

Almost surely, 2^20218313 is an apocalyptic number.

It is an amenable number.

20218313 is a deficient number, since it is larger than the sum of its proper divisors (1).

20218313 is an equidigital number, since it uses as much as digits as its factorization.

20218313 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 20218313 is about 4496.4778438240. The cubic root of 20218313 is about 272.4258440867.

Adding to 20218313 its reverse (31381202), we get a palindrome (51599515).

The spelling of 20218313 in words is "twenty million, two hundred eighteen thousand, three hundred thirteen".