20319725509 has 2 divisors, whose sum is σ = 20319725510. Its totient is φ = 20319725508.

The previous prime is 20319725483. The next prime is 20319725513. The reversal of 20319725509 is 90552791302.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19017237409 + 1302488100 = 137903^2 + 36090^2 .

It is a cyclic number.

It is not a de Polignac number, because 20319725509 - 2⁵ = 20319725477 is a prime.

It is a super-2 number, since 2×20319725509² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20319725519) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10159862754 + 10159862755.

It is an arithmetic number, because the mean of its divisors is an integer number (10159862755).

Almost surely, 2^20319725509 is an apocalyptic number.

It is an amenable number.

20319725509 is a deficient number, since it is larger than the sum of its proper divisors (1).

20319725509 is an equidigital number, since it uses as much as digits as its factorization.

20319725509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 170100, while the sum is 43.

The spelling of 20319725509 in words is "twenty billion, three hundred nineteen million, seven hundred twenty-five thousand, five hundred nine".