18644614479481 has 9 divisors (see below), whose sum is σ = 18709734730701. Its totient is φ = 18579720144192.

The previous prime is 18644614479443. The next prime is 18644614479487. The reversal of 18644614479481 is 18497441644681.

The square root of 18644614479481 is 4317941.

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 12133441589481 + 6511172890000 = 3483309^2 + 2551700^2 .

It is not a de Polignac number, because 18644614479481 - 2¹³ = 18644614471289 is a prime.

It is a super-2 number, since 2×18644614479481² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18644614479487) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1265149345 + ... + 1265164081.

Almost surely, 2^{18644614479481} is an apocalyptic number.

18644614479481 is the 4317941-st square number.

18644614479481 is the 2158971-st centered octagonal number.

It is an amenable number.

18644614479481 is a deficient number, since it is larger than the sum of its proper divisors (65120251220).

18644614479481 is an frugal number, since it uses more digits than its factorization.

18644614479481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30060 (or 15030 counting only the distinct ones).

The product of its digits is 148635648, while the sum is 67.

The spelling of 18644614479481 in words is "eighteen trillion, six hundred forty-four billion, six hundred fourteen million, four hundred seventy-nine thousand, four hundred eighty-one".