172821081600 has 1200 divisors, whose sum is σ = 697462740480. Its totient is φ = 42102374400.

The previous prime is 172821081577. The next prime is 172821081607. The reversal of 172821081600 is 6180128271.

172821081600 is a `hidden beast` number, since 1 + 7 + 28 + 21 + 0 + 8 + 1 + 600 = 666.

It is a tau number, because it is divible by the number of its divisors (1200).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172821081607) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 610675059 + ... + 610675341.

Almost surely, 2^172821081600 is an apocalyptic number.

172821081600 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 172821081600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (348731370240).

172821081600 is an abundant number, since it is smaller than the sum of its proper divisors (524641658880).

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

172821081600 is a wasteful number, since it uses less digits than its factorization.

172821081600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 373 (or 343 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 36.

The spelling of 172821081600 in words is "one hundred seventy-two billion, eight hundred twenty-one million, eighty-one thousand, six hundred".