21915595975680 has 1584 divisors, whose sum is σ = 86885117669376. Its totient is φ = 5259751096320.

The previous prime is 21915595975661. The next prime is 21915595975699. The reversal of 21915595975680 is 8657959551912.

21915595975680 is a `hidden beast` number, since 2 + 1 + 9 + 1 + 5 + 5 + 9 + 59 + 7 + 568 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (21915595975661) and next prime (21915595975699).

It is a tau number, because it is divible by the number of its divisors (1584).

It is a super-2 number, since 2×21915595975680² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 21915595975599 and 21915595975608.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 46928470807 + ... + 46928471273.

Almost surely, 2^{21915595975680} is an apocalyptic number.

21915595975680 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 21915595975680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43442558834688).

21915595975680 is an abundant number, since it is smaller than the sum of its proper divisors (64969521693696).

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

21915595975680 is an equidigital number, since it uses as much as digits as its factorization.

21915595975680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 654 (or 615 counting only the distinct ones).

The product of its (nonzero) digits is 306180000, while the sum is 72.

The spelling of 21915595975680 in words is "twenty-one trillion, nine hundred fifteen billion, five hundred ninety-five million, nine hundred seventy-five thousand, six hundred eighty".