21387382665600 has 768 divisors, whose sum is σ = 81611533670400. Its totient is φ = 4821821030400.

The previous prime is 21387382665577. The next prime is 21387382665613. The reversal of 21387382665600 is 656628378312.

It is a super-2 number, since 2×21387382665600² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2577720652 + ... + 2577728948.

It is an arithmetic number, because the mean of its divisors is an integer number (106265017800).

Almost surely, 2^{21387382665600} is an apocalyptic number.

21387382665600 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 21387382665600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40805766835200).

21387382665600 is an abundant number, since it is smaller than the sum of its proper divisors (60224151004800).

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

21387382665600 is a wasteful number, since it uses less digits than its factorization.

21387382665600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8851 (or 8834 counting only the distinct ones).

The product of its (nonzero) digits is 17418240, while the sum is 57.

The spelling of 21387382665600 in words is "twenty-one trillion, three hundred eighty-seven billion, three hundred eighty-two million, six hundred sixty-five thousand, six hundred".