20338181 has 2 divisors, whose sum is σ = 20338182. Its totient is φ = 20338180.

The previous prime is 20338133. The next prime is 20338207. The reversal of 20338181 is 18183302.

It is an a-pointer prime, because the next prime (20338207) can be obtained adding 20338181 to its sum of digits (26).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19936225 + 401956 = 4465^2 + 634^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20338181 is a prime.

It is a super-2 number, since 2×20338181² = 827283212777522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20338181.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20338111) 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, 10169090 + 10169091.

It is an arithmetic number, because the mean of its divisors is an integer number (10169091).

Almost surely, 2^20338181 is an apocalyptic number.

It is an amenable number.

20338181 is a deficient number, since it is larger than the sum of its proper divisors (1).

20338181 is an equidigital number, since it uses as much as digits as its factorization.

20338181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 20338181 is about 4509.7872455361. The cubic root of 20338181 is about 272.9631592555.

The spelling of 20338181 in words is "twenty million, three hundred thirty-eight thousand, one hundred eighty-one".