21525645127680 has 1664 divisors, whose sum is σ = 82327491993600. Its totient is φ = 5391970467840.

The previous prime is 21525645127673. The next prime is 21525645127687. The reversal of 21525645127680 is 8672154652512.

21525645127680 is a `hidden beast` number, since 2 + 1 + 5 + 2 + 5 + 64 + 512 + 7 + 68 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (21525645127673) and next prime (21525645127687).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21525645127687) 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 127 ways as a sum of consecutive naturals, for example, 51373854511 + ... + 51373854929.

Almost surely, 2^{21525645127680} is an apocalyptic number.

21525645127680 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 21525645127680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41163745996800).

21525645127680 is an abundant number, since it is smaller than the sum of its proper divisors (60801846865920).

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

21525645127680 is an frugal number, since it uses more digits than its factorization.

21525645127680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 537 (or 497 counting only the distinct ones).

The product of its (nonzero) digits is 8064000, while the sum is 54.

The spelling of 21525645127680 in words is "twenty-one trillion, five hundred twenty-five billion, six hundred forty-five million, one hundred twenty-seven thousand, six hundred eighty".