18736249874521 has 3 divisors (see below), whose sum is σ = 18736254203061. Its totient is φ = 18736245545982.

The previous prime is 18736249874477. The next prime is 18736249874527. The reversal of 18736249874521 is 12547894263781.

The square root of 18736249874521 is 4328539.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 18736249874521 - 2¹⁹ = 18736249350233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18736249874527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2164270 + ... + 6492808.

It is an arithmetic number, because the mean of its divisors is an integer number (6245418067687).

Almost surely, 2^{18736249874521} is an apocalyptic number.

18736249874521 is the 4328539-th square number.

18736249874521 is the 2164270-th centered octagonal number.

It is an amenable number.

18736249874521 is a deficient number, since it is larger than the sum of its proper divisors (4328540).

18736249874521 is an frugal number, since it uses more digits than its factorization.

18736249874521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8657078 (or 4328539 counting only the distinct ones).

The product of its digits is 162570240, while the sum is 67.

The spelling of 18736249874521 in words is "eighteen trillion, seven hundred thirty-six billion, two hundred forty-nine million, eight hundred seventy-four thousand, five hundred twenty-one".