18640989659 has 4 divisors (see below), whose sum is σ = 18643280304. Its totient is φ = 18638699016.

The previous prime is 18640989629. The next prime is 18640989667. The reversal of 18640989659 is 95698904681.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18640989659 - 2¹² = 18640985563 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18640989595 and 18640989604.

It is not an unprimeable number, because it can be changed into a prime (18640989629) 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, 1133072 + ... + 1149405.

It is an arithmetic number, because the mean of its divisors is an integer number (4660820076).

Almost surely, 2^18640989659 is an apocalyptic number.

18640989659 is a deficient number, since it is larger than the sum of its proper divisors (2290645).

18640989659 is an equidigital number, since it uses as much as digits as its factorization.

18640989659 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2290644.

The product of its (nonzero) digits is 33592320, while the sum is 65.

The spelling of 18640989659 in words is "eighteen billion, six hundred forty million, nine hundred eighty-nine thousand, six hundred fifty-nine".