20613533 has 2 divisors, whose sum is σ = 20613534. Its totient is φ = 20613532.

The previous prime is 20613491. The next prime is 20613563. The reversal of 20613533 is 33531602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18645124 + 1968409 = 4318^2 + 1403^2 .

It is a cyclic number.

It is not a de Polignac number, because 20613533 - 2¹⁶ = 20547997 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20613499 and 20613508.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20613563) 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, 10306766 + 10306767.

It is an arithmetic number, because the mean of its divisors is an integer number (10306767).

Almost surely, 2^20613533 is an apocalyptic number.

It is an amenable number.

20613533 is a deficient number, since it is larger than the sum of its proper divisors (1).

20613533 is an equidigital number, since it uses as much as digits as its factorization.

20613533 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1620, while the sum is 23.

The square root of 20613533 is about 4540.2128804716. The cubic root of 20613533 is about 274.1894945418.

The spelling of 20613533 in words is "twenty million, six hundred thirteen thousand, five hundred thirty-three".