18685684130989 has 4 divisors (see below), whose sum is σ = 18685728818460. Its totient is φ = 18685639443520.

The previous prime is 18685684130983. The next prime is 18685684131007. The reversal of 18685684130989 is 98903148658681.

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 3840522075625 + 14845162055364 = 1959725^2 + 3852942^2 .

It is a cyclic number.

It is not a de Polignac number, because 18685684130989 - 2¹³ = 18685684122797 is a prime.

It is a super-2 number, since 2×18685684130989² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18685684130983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21710542 + ... + 22554799.

It is an arithmetic number, because the mean of its divisors is an integer number (4671432204615).

Almost surely, 2^{18685684130989} is an apocalyptic number.

It is an amenable number.

18685684130989 is a deficient number, since it is larger than the sum of its proper divisors (44687471).

18685684130989 is an equidigital number, since it uses as much as digits as its factorization.

18685684130989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44687470.

The product of its (nonzero) digits is 716636160, while the sum is 76.

The spelling of 18685684130989 in words is "eighteen trillion, six hundred eighty-five billion, six hundred eighty-four million, one hundred thirty thousand, nine hundred eighty-nine".