20412181 has 2 divisors, whose sum is σ = 20412182. Its totient is φ = 20412180.

The previous prime is 20412179. The next prime is 20412191. The reversal of 20412181 is 18121402.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10432900 + 9979281 = 3230^2 + 3159^2 .

It is a cyclic number.

It is not a de Polignac number, because 20412181 - 2¹ = 20412179 is a prime.

It is a super-2 number, since 2×20412181² = 833314266353522, which contains 22 as substring.

Together with 20412179, 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 (20412101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10206090 + 10206091.

It is an arithmetic number, because the mean of its divisors is an integer number (10206091).

Almost surely, 2^20412181 is an apocalyptic number.

It is an amenable number.

20412181 is a deficient number, since it is larger than the sum of its proper divisors (1).

20412181 is an equidigital number, since it uses as much as digits as its factorization.

20412181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 128, while the sum is 19.

The square root of 20412181 is about 4517.9841743857. The cubic root of 20412181 is about 273.2938152598.

Adding to 20412181 its reverse (18121402), we get a palindrome (38533583).

The spelling of 20412181 in words is "twenty million, four hundred twelve thousand, one hundred eighty-one".