18747836209 has 2 divisors, whose sum is σ = 18747836210. Its totient is φ = 18747836208.

The previous prime is 18747836089. The next prime is 18747836243. The reversal of 18747836209 is 90263874781.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18501440400 + 246395809 = 136020^2 + 15697^2 .

It is a cyclic number.

It is not a de Polignac number, because 18747836209 - 2¹⁵ = 18747803441 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18747836209.

It is not a weakly prime, because it can be changed into another prime (18747830209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9373918104 + 9373918105.

It is an arithmetic number, because the mean of its divisors is an integer number (9373918105).

Almost surely, 2^18747836209 is an apocalyptic number.

It is an amenable number.

18747836209 is a deficient number, since it is larger than the sum of its proper divisors (1).

18747836209 is an equidigital number, since it uses as much as digits as its factorization.

18747836209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4064256, while the sum is 55.

The spelling of 18747836209 in words is "eighteen billion, seven hundred forty-seven million, eight hundred thirty-six thousand, two hundred nine".