18315973502993 has 4 divisors (see below), whose sum is σ = 18349829277108. Its totient is φ = 18282117728880.

The previous prime is 18315973502951. The next prime is 18315973503011. The reversal of 18315973502993 is 39920537951381.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9522951621184 + 8793021881809 = 3085928^2 + 2965303^2 .

It is a cyclic number.

It is not a de Polignac number, because 18315973502993 - 2⁶ = 18315973502929 is a prime.

It is a super-3 number, since 3×18315973502993³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18315973502093) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16927886246 + ... + 16927887327.

It is an arithmetic number, because the mean of its divisors is an integer number (4587457319277).

Almost surely, 2^{18315973502993} is an apocalyptic number.

It is an amenable number.

18315973502993 is a deficient number, since it is larger than the sum of its proper divisors (33855774115).

18315973502993 is an equidigital number, since it uses as much as digits as its factorization.

18315973502993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33855774114.

The product of its (nonzero) digits is 55112400, while the sum is 65.

The spelling of 18315973502993 in words is "eighteen trillion, three hundred fifteen billion, nine hundred seventy-three million, five hundred two thousand, nine hundred ninety-three".