18977317728 has 48 divisors (see below), whose sum is σ = 51030480816. Its totient is φ = 6171484160.

The previous prime is 18977317691. The next prime is 18977317729. The reversal of 18977317728 is 82771377981.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18977317729) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2406801 + ... + 2414672.

It is an arithmetic number, because the mean of its divisors is an integer number (1063135017).

Almost surely, 2^18977317728 is an apocalyptic number.

It is an amenable number.

18977317728 is an abundant number, since it is smaller than the sum of its proper divisors (32053163088).

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

18977317728 is a wasteful number, since it uses less digits than its factorization.

18977317728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4821527 (or 4821519 counting only the distinct ones).

The product of its digits is 8297856, while the sum is 60.

The spelling of 18977317728 in words is "eighteen billion, nine hundred seventy-seven million, three hundred seventeen thousand, seven hundred twenty-eight".