20456221 has 2 divisors, whose sum is σ = 20456222. Its totient is φ = 20456220.

The previous prime is 20456209. The next prime is 20456231. The reversal of 20456221 is 12265402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16088121 + 4368100 = 4011^2 + 2090^2 .

It is a cyclic number.

It is not a de Polignac number, because 20456221 - 2¹¹ = 20454173 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20456192 and 20456201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20456231) 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, 10228110 + 10228111.

It is an arithmetic number, because the mean of its divisors is an integer number (10228111).

Almost surely, 2^20456221 is an apocalyptic number.

It is an amenable number.

20456221 is a deficient number, since it is larger than the sum of its proper divisors (1).

20456221 is an equidigital number, since it uses as much as digits as its factorization.

20456221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 20456221 is about 4522.8554033929. The cubic root of 20456221 is about 273.4902210898.

The spelling of 20456221 in words is "twenty million, four hundred fifty-six thousand, two hundred twenty-one".