18680318761 has 16 divisors (see below), whose sum is σ = 20247315088. Its totient is φ = 17132083200.

The previous prime is 18680318693. The next prime is 18680318821. The reversal of 18680318761 is 16781308681.

18680318761 = 96644² + 96645².

It can be written as a sum of positive squares in 8 ways, for example, as 2708161600 + 15972157161 = 52040^2 + 126381^2 .

It is a 9-Lehmer number, since φ(18680318761) divides (18680318761-1)⁹.

It is a cyclic number.

It is not a de Polignac number, because 18680318761 - 2¹³ = 18680310569 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18680318561) 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 15 ways as a sum of consecutive naturals, for example, 3048781 + ... + 3054901.

It is an arithmetic number, because the mean of its divisors is an integer number (1265457193).

Almost surely, 2^18680318761 is an apocalyptic number.

18680318761 is the 96645-th centered square number.

It is an amenable number.

18680318761 is a deficient number, since it is larger than the sum of its proper divisors (1566996327).

18680318761 is a wasteful number, since it uses less digits than its factorization.

18680318761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7612.

The product of its (nonzero) digits is 387072, while the sum is 49.

The spelling of 18680318761 in words is "eighteen billion, six hundred eighty million, three hundred eighteen thousand, seven hundred sixty-one".