18385325729 has 4 divisors (see below), whose sum is σ = 18398835780. Its totient is φ = 18371815680.

The previous prime is 18385325723. The next prime is 18385325731. The reversal of 18385325729 is 92752358381.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 92752358381 = 757 ⋅122526233.

It can be written as a sum of positive squares in 2 ways, for example, as 4941387025 + 13443938704 = 70295^2 + 115948^2 .

It is a cyclic number.

It is not a de Polignac number, because 18385325729 - 2²⁸ = 18116890273 is a prime.

It is a super-2 number, since 2×18385325729² (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 (18385325723) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6752984 + ... + 6755705.

It is an arithmetic number, because the mean of its divisors is an integer number (4599708945).

Almost surely, 2^18385325729 is an apocalyptic number.

It is an amenable number.

18385325729 is a deficient number, since it is larger than the sum of its proper divisors (13510051).

18385325729 is a wasteful number, since it uses less digits than its factorization.

18385325729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13510050.

The product of its digits is 3628800, while the sum is 53.

The spelling of 18385325729 in words is "eighteen billion, three hundred eighty-five million, three hundred twenty-five thousand, seven hundred twenty-nine".