18161087616 has 192 divisors, whose sum is σ = 61653696000. Its totient is φ = 5021429760.

The previous prime is 18161087611. The next prime is 18161087621. The reversal of 18161087616 is 61678016181.

18161087616 is a `hidden beast` number, since 1 + 8 + 16 + 10 + 8 + 7 + 616 = 666.

It is an interprime number because it is at equal distance from previous prime (18161087611) and next prime (18161087621).

It is a tau number, because it is divible by the number of its divisors (192).

It is not an unprimeable number, because it can be changed into a prime (18161087611) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 213660 + ... + 286308.

It is an arithmetic number, because the mean of its divisors is an integer number (321113000).

Almost surely, 2^18161087616 is an apocalyptic number.

18161087616 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 18161087616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30826848000).

18161087616 is an abundant number, since it is smaller than the sum of its proper divisors (43492608384).

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

18161087616 is a wasteful number, since it uses less digits than its factorization.

18161087616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72707 (or 72692 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 45.

The spelling of 18161087616 in words is "eighteen billion, one hundred sixty-one million, eighty-seven thousand, six hundred sixteen".