20557633 has 2 divisors, whose sum is σ = 20557634. Its totient is φ = 20557632.

The previous prime is 20557627. The next prime is 20557637. The reversal of 20557633 is 33675502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12588304 + 7969329 = 3548^2 + 2823^2 .

It is a cyclic number.

It is not a de Polignac number, because 20557633 - 2¹⁷ = 20426561 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20557595 and 20557604.

It is not a weakly prime, because it can be changed into another prime (20557637) 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, 10278816 + 10278817.

It is an arithmetic number, because the mean of its divisors is an integer number (10278817).

Almost surely, 2^20557633 is an apocalyptic number.

It is an amenable number.

20557633 is a deficient number, since it is larger than the sum of its proper divisors (1).

20557633 is an equidigital number, since it uses as much as digits as its factorization.

20557633 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18900, while the sum is 31.

The square root of 20557633 is about 4534.0526022533. The cubic root of 20557633 is about 273.9414201584.

The spelling of 20557633 in words is "twenty million, five hundred fifty-seven thousand, six hundred thirty-three".