21385531564320 has 1152 divisors, whose sum is σ = 91791404070912. Its totient is φ = 4123383398400.

The previous prime is 21385531564307. The next prime is 21385531564339. The reversal of 21385531564320 is 2346513558312.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 21385531564320.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 312240799 + ... + 312309281.

It is an arithmetic number, because the mean of its divisors is an integer number (79680038256).

Almost surely, 2^{21385531564320} is an apocalyptic number.

21385531564320 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 21385531564320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45895702035456).

21385531564320 is an abundant number, since it is smaller than the sum of its proper divisors (70405872506592).

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

21385531564320 is a wasteful number, since it uses less digits than its factorization.

21385531564320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68614 (or 68599 counting only the distinct ones).

The product of its (nonzero) digits is 2592000, while the sum is 48.

The spelling of 21385531564320 in words is "twenty-one trillion, three hundred eighty-five billion, five hundred thirty-one million, five hundred sixty-four thousand, three hundred twenty".