20013773516509 has 2 divisors, whose sum is σ = 20013773516510. Its totient is φ = 20013773516508.

The previous prime is 20013773516489. The next prime is 20013773516543. The reversal of 20013773516509 is 90561537731002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15848002712025 + 4165770804484 = 3980955^2 + 2041022^2 .

It is a cyclic number.

It is not a de Polignac number, because 20013773516509 - 2⁷ = 20013773516381 is a prime.

It is a super-2 number, since 2×20013773516509² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20013773546509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10006886758254 + 10006886758255.

It is an arithmetic number, because the mean of its divisors is an integer number (10006886758255).

Almost surely, 2^{20013773516509} is an apocalyptic number.

It is an amenable number.

20013773516509 is a deficient number, since it is larger than the sum of its proper divisors (1).

20013773516509 is an equidigital number, since it uses as much as digits as its factorization.

20013773516509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1190700, while the sum is 49.

The spelling of 20013773516509 in words is "twenty trillion, thirteen billion, seven hundred seventy-three million, five hundred sixteen thousand, five hundred nine".