18489481553 has 4 divisors (see below), whose sum is σ = 18502476288. Its totient is φ = 18476486820.

The previous prime is 18489481519. The next prime is 18489481583. The reversal of 18489481553 is 35518498481.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18489481553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18489481513) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6495233 + ... + 6498078.

It is an arithmetic number, because the mean of its divisors is an integer number (4625619072).

Almost surely, 2^18489481553 is an apocalyptic number.

It is an amenable number.

18489481553 is a deficient number, since it is larger than the sum of its proper divisors (12994735).

18489481553 is a wasteful number, since it uses less digits than its factorization.

18489481553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12994734.

The product of its digits is 5529600, while the sum is 56.

The spelling of 18489481553 in words is "eighteen billion, four hundred eighty-nine million, four hundred eighty-one thousand, five hundred fifty-three".