21273171987600 has 960 divisors, whose sum is σ = 85201766737920. Its totient is φ = 5002008422400.

The previous prime is 21273171987569. The next prime is 21273171987631. The reversal of 21273171987600 is 678917137212.

21273171987600 is a `hidden beast` number, since 2 + 1 + 2 + 7 + 3 + 17 + 19 + 8 + 7 + 600 = 666.

It is an interprime number because it is at equal distance from previous prime (21273171987569) and next prime (21273171987631).

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

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 191 ways as a sum of consecutive naturals, for example, 2618877139 + ... + 2618885261.

It is an arithmetic number, because the mean of its divisors is an integer number (88751840352).

Almost surely, 2^{21273171987600} is an apocalyptic number.

21273171987600 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 21273171987600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42600883368960).

21273171987600 is an abundant number, since it is smaller than the sum of its proper divisors (63928594750320).

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

21273171987600 is a wasteful number, since it uses less digits than its factorization.

21273171987600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8997 (or 8980 counting only the distinct ones).

The product of its (nonzero) digits is 1778112, while the sum is 54.

The spelling of 21273171987600 in words is "twenty-one trillion, two hundred seventy-three billion, one hundred seventy-one million, nine hundred eighty-seven thousand, six hundred".