21579219728640 has 1728 divisors, whose sum is σ = 90249333753600. Its totient is φ = 4868114743296.

The previous prime is 21579219728587. The next prime is 21579219728707. The reversal of 21579219728640 is 4682791297512.

21579219728640 is a `hidden beast` number, since 2 + 1 + 579 + 2 + 19 + 7 + 2 + 8 + 6 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (1728).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 77903320182 + ... + 77903320458.

It is an arithmetic number, because the mean of its divisors is an integer number (52227623700).

Almost surely, 2^{21579219728640} is an apocalyptic number.

21579219728640 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 21579219728640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45124666876800).

21579219728640 is an abundant number, since it is smaller than the sum of its proper divisors (68670114024960).

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

21579219728640 is a wasteful number, since it uses less digits than its factorization.

21579219728640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 757 (or 730 counting only the distinct ones).

The product of its (nonzero) digits is 30481920, while the sum is 63.

The spelling of 21579219728640 in words is "twenty-one trillion, five hundred seventy-nine billion, two hundred nineteen million, seven hundred twenty-eight thousand, six hundred forty".