18161589600 has 1728 divisors, whose sum is σ = 88446339072. Its totient is φ = 3391488000.

The previous prime is 18161589571. The next prime is 18161589703. The reversal of 18161589600 is 698516181.

18161589600 is a `hidden beast` number, since 1 + 8 + 1 + 6 + 1 + 589 + 60 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 386416777 + ... + 386416823.

It is an arithmetic number, because the mean of its divisors is an integer number (51184224).

Almost surely, 2^18161589600 is an apocalyptic number.

18161589600 is a gapful number since it is divisible by the number (10) 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 18161589600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44223169536).

18161589600 is an abundant number, since it is smaller than the sum of its proper divisors (70284749472).

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

18161589600 is a wasteful number, since it uses less digits than its factorization.

18161589600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149 (or 133 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 45.

The spelling of 18161589600 in words is "eighteen billion, one hundred sixty-one million, five hundred eighty-nine thousand, six hundred".