21315382704240 has 160 divisors (see below), whose sum is σ = 66540187584000. Its totient is φ = 5644338846720.

The previous prime is 21315382704223. The next prime is 21315382704247. The reversal of 21315382704240 is 4240728351312.

It is a junction number, because it is equal to n+sod(n) for n = 21315382704192 and 21315382704201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21315382704247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 127615501 + ... + 127782419.

It is an arithmetic number, because the mean of its divisors is an integer number (415876172400).

Almost surely, 2^{21315382704240} is an apocalyptic number.

21315382704240 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 21315382704240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33270093792000).

21315382704240 is an abundant number, since it is smaller than the sum of its proper divisors (45224804879760).

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

21315382704240 is a wasteful number, since it uses less digits than its factorization.

21315382704240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170655 (or 170649 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 42.

The spelling of 21315382704240 in words is "twenty-one trillion, three hundred fifteen billion, three hundred eighty-two million, seven hundred four thousand, two hundred forty".