18520379685 has 24 divisors (see below), whose sum is σ = 32140873440. Its totient is φ = 9865572192.

The previous prime is 18520379651. The next prime is 18520379687. The reversal of 18520379685 is 58697302581.

18520379685 is a `hidden beast` number, since 1 + 8 + 520 + 37 + 9 + 6 + 85 = 666.

It is not a de Polignac number, because 18520379685 - 2⁸ = 18520379429 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18520379687) 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, 211615 + ... + 286044.

It is an arithmetic number, because the mean of its divisors is an integer number (1339203060).

Almost surely, 2^18520379685 is an apocalyptic number.

18520379685 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18520379685 is a deficient number, since it is larger than the sum of its proper divisors (13620493755).

18520379685 is a wasteful number, since it uses less digits than its factorization.

18520379685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 498497 (or 498494 counting only the distinct ones).

The product of its (nonzero) digits is 3628800, while the sum is 54.

The spelling of 18520379685 in words is "eighteen billion, five hundred twenty million, three hundred seventy-nine thousand, six hundred eighty-five".