21539281464720 has 800 divisors, whose sum is σ = 82201274496000. Its totient is φ = 5206720020480.

The previous prime is 21539281464653. The next prime is 21539281464721. The reversal of 21539281464720 is 2746418293512.

It is a happy number.

21539281464720 is a `hidden beast` number, since 2 + 1 + 5 + 3 + 9 + 28 + 146 + 472 + 0 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (21539281464721) by changing a digit.

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 159 ways as a sum of consecutive naturals, for example, 339656376 + ... + 339719784.

It is an arithmetic number, because the mean of its divisors is an integer number (102751593120).

It is a 1-persistent number, because it is pandigital, but 2⋅21539281464720 = 43078562929440 is not.

Almost surely, 2^{21539281464720} is an apocalyptic number.

21539281464720 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 21539281464720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41100637248000).

21539281464720 is an abundant number, since it is smaller than the sum of its proper divisors (60661993031280).

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

21539281464720 is a wasteful number, since it uses less digits than its factorization.

21539281464720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63573 (or 63558 counting only the distinct ones).

The product of its (nonzero) digits is 5806080, while the sum is 54.

The spelling of 21539281464720 in words is "twenty-one trillion, five hundred thirty-nine billion, two hundred eighty-one million, four hundred sixty-four thousand, seven hundred twenty".