21563161528320 has 576 divisors, whose sum is σ = 80174720808000. Its totient is φ = 5551875883008.

The previous prime is 21563161528309. The next prime is 21563161528331. The reversal of 21563161528320 is 2382516136512.

It is a happy number.

21563161528320 is a `hidden beast` number, since 2 + 1 + 5 + 6 + 3 + 1 + 615 + 2 + 8 + 3 + 20 = 666.

It is an interprime number because it is at equal distance from previous prime (21563161528309) and next prime (21563161528331).

It is a tau number, because it is divible by the number of its divisors (576).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 72011871 + ... + 72310689.

It is an arithmetic number, because the mean of its divisors is an integer number (139192223625).

Almost surely, 2^{21563161528320} is an apocalyptic number.

21563161528320 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 21563161528320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40087360404000).

21563161528320 is an abundant number, since it is smaller than the sum of its proper divisors (58611559279680).

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

21563161528320 is an equidigital number, since it uses as much as digits as its factorization.

21563161528320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 298890 (or 298858 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 45.

The spelling of 21563161528320 in words is "twenty-one trillion, five hundred sixty-three billion, one hundred sixty-one million, five hundred twenty-eight thousand, three hundred twenty".