21128170291200 has 2160 divisors, whose sum is σ = 91304862781440. Its totient is φ = 4775663370240.

The previous prime is 21128170291199. The next prime is 21128170291259. The reversal of 21128170291200 is 219207182112.

21128170291200 is a `hidden beast` number, since 2 + 1 + 1 + 281 + 70 + 291 + 20 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (2160).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 68821401447 + ... + 68821401753.

Almost surely, 2^{21128170291200} is an apocalyptic number.

21128170291200 is a gapful number since it is divisible by the number (20) 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 21128170291200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45652431390720).

21128170291200 is an abundant number, since it is smaller than the sum of its proper divisors (70176692490240).

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

21128170291200 is a wasteful number, since it uses less digits than its factorization.

21128170291200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 495 (or 451 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 36.

The spelling of 21128170291200 in words is "twenty-one trillion, one hundred twenty-eight billion, one hundred seventy million, two hundred ninety-one thousand, two hundred".