20393509 has 2 divisors, whose sum is σ = 20393510. Its totient is φ = 20393508.

The previous prime is 20393507. The next prime is 20393521. The reversal of 20393509 is 90539302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12271009 + 8122500 = 3503^2 + 2850^2 .

It is a cyclic number.

It is not a de Polignac number, because 20393509 - 2¹ = 20393507 is a prime.

Together with 20393507, 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 (20393507) 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, 10196754 + 10196755.

It is an arithmetic number, because the mean of its divisors is an integer number (10196755).

Almost surely, 2^20393509 is an apocalyptic number.

It is an amenable number.

20393509 is a deficient number, since it is larger than the sum of its proper divisors (1).

20393509 is an equidigital number, since it uses as much as digits as its factorization.

20393509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7290, while the sum is 31.

The square root of 20393509 is about 4515.9172933082. The cubic root of 20393509 is about 273.2104581885.

It can be divided in two parts, 20393 and 509, that added together give a palindrome (20902).

The spelling of 20393509 in words is "twenty million, three hundred ninety-three thousand, five hundred nine".