21385551156480 has 2160 divisors, whose sum is σ = 94731601567680. Its totient is φ = 4596074348544.

The previous prime is 21385551156457. The next prime is 21385551156493. The reversal of 21385551156480 is 8465115558312.

21385551156480 is a `hidden beast` number, since 2 + 1 + 3 + 8 + 5 + 5 + 5 + 1 + 156 + 480 = 666.

It is a tau number, because it is divible by the number of its divisors (2160).

It is a super-3 number, since 3×21385551156480³ (a number of 41 digits) contains 333 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 239 ways as a sum of consecutive naturals, for example, 20986801411 + ... + 20986802429.

It is an arithmetic number, because the mean of its divisors is an integer number (43857222948).

Almost surely, 2^{21385551156480} is an apocalyptic number.

21385551156480 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 21385551156480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47365800783840).

21385551156480 is an abundant number, since it is smaller than the sum of its proper divisors (73346050411200).

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

21385551156480 is an frugal number, since it uses more digits than its factorization.

21385551156480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1098 (or 1053 counting only the distinct ones).

The product of its (nonzero) digits is 5760000, while the sum is 54.

The spelling of 21385551156480 in words is "twenty-one trillion, three hundred eighty-five billion, five hundred fifty-one million, one hundred fifty-six thousand, four hundred eighty".