18023643945 has 24 divisors (see below), whose sum is σ = 31284489600. Its totient is φ = 9599223456.

The previous prime is 18023643857. The next prime is 18023643947. The reversal of 18023643945 is 54934632081.

18023643945 is a `hidden beast` number, since 180 + 2 + 36 + 439 + 4 + 5 = 666.

It is not a de Polignac number, because 18023643945 - 2¹⁰ = 18023642921 is a prime.

It is a super-2 number, since 2×18023643945² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 18023643945.

It is not an unprimeable number, because it can be changed into a prime (18023643947) 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 23 ways as a sum of consecutive naturals, for example, 246175 + ... + 310884.

It is an arithmetic number, because the mean of its divisors is an integer number (1303520400).

Almost surely, 2^18023643945 is an apocalyptic number.

18023643945 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18023643945 is a deficient number, since it is larger than the sum of its proper divisors (13260845655).

18023643945 is a wasteful number, since it uses less digits than its factorization.

18023643945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 557789 (or 557786 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 45.

The spelling of 18023643945 in words is "eighteen billion, twenty-three million, six hundred forty-three thousand, nine hundred forty-five".