17994309481 has 4 divisors (see below), whose sum is σ = 19052798292. Its totient is φ = 16935820672.

The previous prime is 17994309457. The next prime is 17994309511. The reversal of 17994309481 is 18490349971.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18490349971 = 307 ⋅60229153.

It can be written as a sum of positive squares in 2 ways, for example, as 8523905625 + 9470403856 = 92325^2 + 97316^2 .

It is a cyclic number.

It is not a de Polignac number, because 17994309481 - 2⁷ = 17994309353 is a prime.

It is a super-2 number, since 2×17994309481² (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 (17994309181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 529244380 + ... + 529244413.

It is an arithmetic number, because the mean of its divisors is an integer number (4763199573).

Almost surely, 2^17994309481 is an apocalyptic number.

It is an amenable number.

17994309481 is a deficient number, since it is larger than the sum of its proper divisors (1058488811).

17994309481 is a wasteful number, since it uses less digits than its factorization.

17994309481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1058488810.

The product of its (nonzero) digits is 1959552, while the sum is 55.

The spelling of 17994309481 in words is "seventeen billion, nine hundred ninety-four million, three hundred nine thousand, four hundred eighty-one".