161728358400 has 1008 divisors, whose sum is σ = 688204389600. Its totient is φ = 36906762240.

The previous prime is 161728358377. The next prime is 161728358401. The reversal of 161728358400 is 4853827161.

161728358400 is a `hidden beast` number, since 1 + 61 + 7 + 2 + 8 + 3 + 584 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1008).

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

It is not an unprimeable number, because it can be changed into a prime (161728358401) by changing a digit.

It is a polite number, since it can be written in 83 ways as a sum of consecutive naturals, for example, 261273291 + ... + 261273909.

It is an arithmetic number, because the mean of its divisors is an integer number (682742450).

Almost surely, 2^161728358400 is an apocalyptic number.

161728358400 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 161728358400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (344102194800).

161728358400 is an abundant number, since it is smaller than the sum of its proper divisors (526476031200).

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

161728358400 is an frugal number, since it uses more digits than its factorization.

161728358400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 676 (or 636 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 45.

The spelling of 161728358400 in words is "one hundred sixty-one billion, seven hundred twenty-eight million, three hundred fifty-eight thousand, four hundred".