21128687769600 has 1728 divisors, whose sum is σ = 81695708640000. Its totient is φ = 5202778521600.

The previous prime is 21128687769559. The next prime is 21128687769611. The reversal of 21128687769600 is 696778682112.

21128687769600 is a `hidden beast` number, since 2 + 1 + 12 + 8 + 6 + 8 + 7 + 7 + 6 + 9 + 600 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 106174310301 + ... + 106174310499.

Almost surely, 2^{21128687769600} is an apocalyptic number.

21128687769600 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 21128687769600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40847854320000).

21128687769600 is an abundant number, since it is smaller than the sum of its proper divisors (60567020870400).

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

21128687769600 is a wasteful number, since it uses less digits than its factorization.

21128687769600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 504 (or 476 counting only the distinct ones).

The product of its (nonzero) digits is 24385536, while the sum is 63.

The spelling of 21128687769600 in words is "twenty-one trillion, one hundred twenty-eight billion, six hundred eighty-seven million, seven hundred sixty-nine thousand, six hundred".