18911980672 has 128 divisors (see below), whose sum is σ = 42309812160. Its totient is φ = 8363077632.

The previous prime is 18911980663. The next prime is 18911980699. The reversal of 18911980672 is 27608911981.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (52).

It is an unprimeable number.

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, 3789763 + ... + 3794749.

Almost surely, 2^18911980672 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18911980672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21154906080).

18911980672 is an abundant number, since it is smaller than the sum of its proper divisors (23397831488).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18911980672 is a wasteful number, since it uses less digits than its factorization.

18911980672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5110 (or 5098 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 52.

The spelling of 18911980672 in words is "eighteen billion, nine hundred eleven million, nine hundred eighty thousand, six hundred seventy-two".