18503305680521 has 16 divisors (see below), whose sum is σ = 20463039072000. Its totient is φ = 16641827440128.

The previous prime is 18503305680511. The next prime is 18503305680527. The reversal of 18503305680521 is 12508650330581.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18503305680521 is a prime.

It is a super-2 number, since 2×18503305680521² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18503305680527) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22146101 + ... + 22966418.

It is an arithmetic number, because the mean of its divisors is an integer number (1278939942000).

Almost surely, 2^{18503305680521} is an apocalyptic number.

It is an amenable number.

18503305680521 is a deficient number, since it is larger than the sum of its proper divisors (1959733391479).

18503305680521 is a wasteful number, since it uses less digits than its factorization.

18503305680521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45113608.

The product of its (nonzero) digits is 864000, while the sum is 47.

The spelling of 18503305680521 in words is "eighteen trillion, five hundred three billion, three hundred five million, six hundred eighty thousand, five hundred twenty-one".