18518516685 has 12 divisors (see below), whose sum is σ = 32098762332. Its totient is φ = 9876542208.

The previous prime is 18518516659. The next prime is 18518516711. The reversal of 18518516685 is 58661581581.

18518516685 is a `hidden beast` number, since 18 + 51 + 8 + 516 + 68 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (18518516659) and next prime (18518516711).

It can be written as a sum of positive squares in 2 ways, for example, as 3635004681 + 14883512004 = 60291^2 + 121998^2 .

It is not a de Polignac number, because 18518516685 - 2¹⁸ = 18518254541 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 205761252 + ... + 205761341.

It is an arithmetic number, because the mean of its divisors is an integer number (2674896861).

Almost surely, 2^18518516685 is an apocalyptic number.

18518516685 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18518516685 is a deficient number, since it is larger than the sum of its proper divisors (13580245647).

18518516685 is a wasteful number, since it uses less digits than its factorization.

18518516685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 411522604 (or 411522601 counting only the distinct ones).

The product of its digits is 2304000, while the sum is 54.

The spelling of 18518516685 in words is "eighteen billion, five hundred eighteen million, five hundred sixteen thousand, six hundred eighty-five".