18789129209 has 2 divisors, whose sum is σ = 18789129210. Its totient is φ = 18789129208.

The previous prime is 18789129143. The next prime is 18789129223. The reversal of 18789129209 is 90292198781.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17674904809 + 1114224400 = 132947^2 + 33380^2 .

It is an emirp because it is prime and its reverse (90292198781) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18789129209 - 2¹⁶ = 18789063673 is a prime.

It is not a weakly prime, because it can be changed into another prime (18789129239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9394564604 + 9394564605.

It is an arithmetic number, because the mean of its divisors is an integer number (9394564605).

Almost surely, 2^18789129209 is an apocalyptic number.

It is an amenable number.

18789129209 is a deficient number, since it is larger than the sum of its proper divisors (1).

18789129209 is an equidigital number, since it uses as much as digits as its factorization.

18789129209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1306368, while the sum is 56.

The spelling of 18789129209 in words is "eighteen billion, seven hundred eighty-nine million, one hundred twenty-nine thousand, two hundred nine".