18728015616 has 144 divisors (see below), whose sum is σ = 57169208320. Its totient is φ = 6041226240.

The previous prime is 18728015573. The next prime is 18728015617. The reversal of 18728015616 is 61651082781.

18728015616 is a `hidden beast` number, since 1 + 8 + 7 + 2 + 80 + 1 + 561 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18728015617) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 170571 + ... + 257973.

Almost surely, 2^18728015616 is an apocalyptic number.

18728015616 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18728015616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28584604160).

18728015616 is an abundant number, since it is smaller than the sum of its proper divisors (38441192704).

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

18728015616 is an equidigital number, since it uses as much as digits as its factorization.

18728015616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87459 (or 87439 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 45.

The spelling of 18728015616 in words is "eighteen billion, seven hundred twenty-eight million, fifteen thousand, six hundred sixteen".