18789547493 has 2 divisors, whose sum is σ = 18789547494. Its totient is φ = 18789547492.

The previous prime is 18789547489. The next prime is 18789547501. The reversal of 18789547493 is 39474598781.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16825462369 + 1964085124 = 129713^2 + 44318^2 .

It is a cyclic number.

It is not a de Polignac number, because 18789547493 - 2² = 18789547489 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18789547433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9394773746 + 9394773747.

It is an arithmetic number, because the mean of its divisors is an integer number (9394773747).

Almost surely, 2^18789547493 is an apocalyptic number.

It is an amenable number.

18789547493 is a deficient number, since it is larger than the sum of its proper divisors (1).

18789547493 is an equidigital number, since it uses as much as digits as its factorization.

18789547493 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60963840, while the sum is 65.

The spelling of 18789547493 in words is "eighteen billion, seven hundred eighty-nine million, five hundred forty-seven thousand, four hundred ninety-three".