20553361 has 2 divisors, whose sum is σ = 20553362. Its totient is φ = 20553360.

The previous prime is 20553359. The next prime is 20553433. The reversal of 20553361 is 16335502.

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., 17850625 + 2702736 = 4225^2 + 1644^2 .

It is a cyclic number.

It is not a de Polignac number, because 20553361 - 2¹ = 20553359 is a prime.

Together with 20553359, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20553301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10276680 + 10276681.

It is an arithmetic number, because the mean of its divisors is an integer number (10276681).

Almost surely, 2^20553361 is an apocalyptic number.

It is an amenable number.

20553361 is a deficient number, since it is larger than the sum of its proper divisors (1).

20553361 is an equidigital number, since it uses as much as digits as its factorization.

20553361 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2700, while the sum is 25.

The square root of 20553361 is about 4533.5814760518. The cubic root of 20553361 is about 273.9224432846.

Adding to 20553361 its reverse (16335502), we get a palindrome (36888863).

The spelling of 20553361 in words is "twenty million, five hundred fifty-three thousand, three hundred sixty-one".