21815720327304 has 640 divisors, whose sum is σ = 70833360660480. Its totient is φ = 6231400243200.

The previous prime is 21815720327279. The next prime is 21815720327329. The reversal of 21815720327304 is 40372302751812.

21815720327304 is a `hidden beast` number, since 2 + 1 + 8 + 1 + 572 + 0 + 3 + 2 + 73 + 0 + 4 = 666.

It is an interprime number because it is at equal distance from previous prime (21815720327279) and next prime (21815720327329).

It is a self number, because there is not a number n which added to its sum of digits gives 21815720327304.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 479096122 + ... + 479141654.

It is an arithmetic number, because the mean of its divisors is an integer number (110677126032).

Almost surely, 2^{21815720327304} is an apocalyptic number.

21815720327304 is a gapful number since it is divisible by the number (24) 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 21815720327304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35416680330240).

21815720327304 is an abundant number, since it is smaller than the sum of its proper divisors (49017640333176).

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

21815720327304 is a wasteful number, since it uses less digits than its factorization.

21815720327304 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45683 (or 45670 counting only the distinct ones).

The product of its (nonzero) digits is 564480, while the sum is 45.

The spelling of 21815720327304 in words is "twenty-one trillion, eight hundred fifteen billion, seven hundred twenty million, three hundred twenty-seven thousand, three hundred four".