21928371978240 has 4096 divisors, whose sum is σ = 104849289216000. Its totient is φ = 4219553710080.

The previous prime is 21928371978211. The next prime is 21928371978313. The reversal of 21928371978240 is 4287917382912.

21928371978240 is a `hidden beast` number, since 2 + 19 + 2 + 8 + 371 + 9 + 7 + 8 + 240 = 666.

It is a tau number, because it is divible by the number of its divisors (4096).

It is a super-2 number, since 2×21928371978240² (a number of 27 digits) contains 22 as substring.

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 255 ways as a sum of consecutive naturals, for example, 359481507810 + ... + 359481507870.

It is an arithmetic number, because the mean of its divisors is an integer number (25597971000).

Almost surely, 2^{21928371978240} is an apocalyptic number.

21928371978240 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 21928371978240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52424644608000).

21928371978240 is an abundant number, since it is smaller than the sum of its proper divisors (82920917237760).

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

21928371978240 is a wasteful number, since it uses less digits than its factorization.

21928371978240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191 (or 157 counting only the distinct ones).

The product of its (nonzero) digits is 24385536, while the sum is 63.

The spelling of 21928371978240 in words is "twenty-one trillion, nine hundred twenty-eight billion, three hundred seventy-one million, nine hundred seventy-eight thousand, two hundred forty".