20436181 has 2 divisors, whose sum is σ = 20436182. Its totient is φ = 20436180.

The previous prime is 20436179. The next prime is 20436187. The reversal of 20436181 is 18163402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17766225 + 2669956 = 4215^2 + 1634^2 .

It is a cyclic number.

It is not a de Polignac number, because 20436181 - 2¹ = 20436179 is a prime.

It is a super-2 number, since 2×20436181² = 835274987729522, which contains 22 as substring.

Together with 20436179, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20436187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10218090 + 10218091.

It is an arithmetic number, because the mean of its divisors is an integer number (10218091).

Almost surely, 2^20436181 is an apocalyptic number.

It is an amenable number.

20436181 is a deficient number, since it is larger than the sum of its proper divisors (1).

20436181 is an equidigital number, since it uses as much as digits as its factorization.

20436181 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 25.

The square root of 20436181 is about 4520.6394459191. The cubic root of 20436181 is about 273.4008833972.

Adding to 20436181 its reverse (18163402), we get a palindrome (38599583).

The spelling of 20436181 in words is "twenty million, four hundred thirty-six thousand, one hundred eighty-one".