21445949558880 has 1728 divisors, whose sum is σ = 100056977879040. Its totient is φ = 4058682163200.

The previous prime is 21445949558837. The next prime is 21445949558893. The reversal of 21445949558880 is 8885594954412.

21445949558880 is a `hidden beast` number, since 2 + 1 + 4 + 4 + 5 + 9 + 495 + 58 + 8 + 80 = 666.

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 = 21445949558799 and 21445949558808.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 993363126 + ... + 993384714.

It is an arithmetic number, because the mean of its divisors is an integer number (57903343680).

Almost surely, 2^{21445949558880} is an apocalyptic number.

21445949558880 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 21445949558880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50028488939520).

21445949558880 is an abundant number, since it is smaller than the sum of its proper divisors (78611028320160).

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

21445949558880 is a wasteful number, since it uses less digits than its factorization.

21445949558880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21693 (or 21665 counting only the distinct ones).

The product of its (nonzero) digits is 663552000, while the sum is 72.

The spelling of 21445949558880 in words is "twenty-one trillion, four hundred forty-five billion, nine hundred forty-nine million, five hundred fifty-eight thousand, eight hundred eighty".