18689445521 has 8 divisors (see below), whose sum is σ = 18814411200. Its totient is φ = 18564674832.

The previous prime is 18689445497. The next prime is 18689445623. The reversal of 18689445521 is 12554498681.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18689445521 - 2¹⁸ = 18689183377 is a prime.

It is a super-2 number, since 2×18689445521² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18689445721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 146180 + ... + 242378.

It is an arithmetic number, because the mean of its divisors is an integer number (2351801400).

Almost surely, 2^18689445521 is an apocalyptic number.

It is an amenable number.

18689445521 is a deficient number, since it is larger than the sum of its proper divisors (124965679).

18689445521 is a wasteful number, since it uses less digits than its factorization.

18689445521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97495.

The product of its digits is 2764800, while the sum is 53.

The spelling of 18689445521 in words is "eighteen billion, six hundred eighty-nine million, four hundred forty-five thousand, five hundred twenty-one".