18297509805 has 24 divisors (see below), whose sum is σ = 31851820728. Its totient is φ = 9716783616.

The previous prime is 18297509773. The next prime is 18297509863. The reversal of 18297509805 is 50890579281.

It can be written as a sum of positive squares in 4 ways, for example, as 2902407876 + 15395101929 = 53874^2 + 124077^2 .

It is not a de Polignac number, because 18297509805 - 2⁵ = 18297509773 is a prime.

It is a super-2 number, since 2×18297509805² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 862072 + ... + 883041.

It is an arithmetic number, because the mean of its divisors is an integer number (1327159197).

Almost surely, 2^18297509805 is an apocalyptic number.

18297509805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18297509805 is a deficient number, since it is larger than the sum of its proper divisors (13554310923).

18297509805 is a wasteful number, since it uses less digits than its factorization.

18297509805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1745357 (or 1745354 counting only the distinct ones).

The product of its (nonzero) digits is 1814400, while the sum is 54.

The spelling of 18297509805 in words is "eighteen billion, two hundred ninety-seven million, five hundred nine thousand, eight hundred five".