18519789949 has 4 divisors (see below), whose sum is σ = 19117202560. Its totient is φ = 17922377340.

The previous prime is 18519789907. The next prime is 18519789971. The reversal of 18519789949 is 94998791581.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18519789949 - 2⁹ = 18519789437 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18519769949) 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, 298706259 + ... + 298706320.

It is an arithmetic number, because the mean of its divisors is an integer number (4779300640).

Almost surely, 2^18519789949 is an apocalyptic number.

It is an amenable number.

18519789949 is a deficient number, since it is larger than the sum of its proper divisors (597412611).

18519789949 is an equidigital number, since it uses as much as digits as its factorization.

18519789949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 597412610.

The product of its digits is 58786560, while the sum is 70.

The spelling of 18519789949 in words is "eighteen billion, five hundred nineteen million, seven hundred eighty-nine thousand, nine hundred forty-nine".