18345519549889 has 27 divisors (see below), whose sum is σ = 22670515220457. Its totient is φ = 14799335679744.

The previous prime is 18345519549829. The next prime is 18345519549893. The reversal of 18345519549889 is 98894591554381.

The square root of 18345519549889 is 4283167.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 8375334396289 + 9970185153600 = 2894017^2 + 3157560^2 .

It is not a de Polignac number, because 18345519549889 - 2⁷ = 18345519549761 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18345519549829) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 509678877 + ... + 509714869.

Almost surely, 2^{18345519549889} is an apocalyptic number.

18345519549889 is the 4283167-th square number.

18345519549889 is the 2141584-th centered octagonal number.

It is an amenable number.

18345519549889 is a deficient number, since it is larger than the sum of its proper divisors (4324995670568).

18345519549889 is an frugal number, since it uses more digits than its factorization.

18345519549889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72034 (or 36017 counting only the distinct ones).

The product of its digits is 2239488000, while the sum is 79.

The spelling of 18345519549889 in words is "eighteen trillion, three hundred forty-five billion, five hundred nineteen million, five hundred forty-nine thousand, eight hundred eighty-nine".