20001255509 has 2 divisors, whose sum is σ = 20001255510. Its totient is φ = 20001255508.

The previous prime is 20001255503. The next prime is 20001255551. The reversal of 20001255509 is 90555210002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12253383025 + 7747872484 = 110695^2 + 88022^2 .

It is a cyclic number.

It is not a de Polignac number, because 20001255509 - 2¹⁶ = 20001189973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20001255503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10000627754 + 10000627755.

It is an arithmetic number, because the mean of its divisors is an integer number (10000627755).

Almost surely, 2^20001255509 is an apocalyptic number.

It is an amenable number.

20001255509 is a deficient number, since it is larger than the sum of its proper divisors (1).

20001255509 is an equidigital number, since it uses as much as digits as its factorization.

20001255509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4500, while the sum is 29.

The spelling of 20001255509 in words is "twenty billion, one million, two hundred fifty-five thousand, five hundred nine".