21271980693600 has 3456 divisors, whose sum is σ = 100282861486080. Its totient is φ = 4279661568000.

The previous prime is 21271980693539. The next prime is 21271980693659. The reversal of 21271980693600 is 639608917212.

21271980693600 is a `hidden beast` number, since 2 + 1 + 27 + 1 + 9 + 8 + 0 + 6 + 9 + 3 + 600 = 666.

It is a super-2 number, since 2×21271980693600² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 575 ways as a sum of consecutive naturals, for example, 43323789355 + ... + 43323789845.

It is an arithmetic number, because the mean of its divisors is an integer number (29017031680).

Almost surely, 2^{21271980693600} is an apocalyptic number.

21271980693600 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 21271980693600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50141430743040).

21271980693600 is an abundant number, since it is smaller than the sum of its proper divisors (79010880792480).

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

21271980693600 is a wasteful number, since it uses less digits than its factorization.

21271980693600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 656 (or 631 counting only the distinct ones).

The product of its (nonzero) digits is 1959552, while the sum is 54.

The spelling of 21271980693600 in words is "twenty-one trillion, two hundred seventy-one billion, nine hundred eighty million, six hundred ninety-three thousand, six hundred".