18729361765 has 4 divisors (see below), whose sum is σ = 22475234124. Its totient is φ = 14983489408.

The previous prime is 18729361747. The next prime is 18729361787. The reversal of 18729361765 is 56716392781.

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 11075036644 + 7654325121 = 105238^2 + 87489^2 .

It is a cyclic number.

It is not a de Polignac number, because 18729361765 - 2¹¹ = 18729359717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 1872936172 + ... + 1872936181.

It is an arithmetic number, because the mean of its divisors is an integer number (5618808531).

Almost surely, 2^18729361765 is an apocalyptic number.

It is an amenable number.

18729361765 is a deficient number, since it is larger than the sum of its proper divisors (3745872359).

18729361765 is an equidigital number, since it uses as much as digits as its factorization.

18729361765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3745872358.

The product of its digits is 3810240, while the sum is 55.

The spelling of 18729361765 in words is "eighteen billion, seven hundred twenty-nine million, three hundred sixty-one thousand, seven hundred sixty-five".