21891575255040 has 832 divisors, whose sum is σ = 79923191040000. Its totient is φ = 5681523326976.

The previous prime is 21891575255027. The next prime is 21891575255089. The reversal of 21891575255040 is 4055257519812.

It is a happy number.

21891575255040 is a `hidden beast` number, since 2 + 1 + 8 + 9 + 1 + 575 + 25 + 5 + 0 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 7299623461 + ... + 7299626459.

Almost surely, 2^{21891575255040} is an apocalyptic number.

21891575255040 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 21891575255040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39961595520000).

21891575255040 is an abundant number, since it is smaller than the sum of its proper divisors (58031615784960).

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

21891575255040 is a wasteful number, since it uses less digits than its factorization.

21891575255040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3387 (or 3359 counting only the distinct ones).

The product of its (nonzero) digits is 5040000, while the sum is 54.

The spelling of 21891575255040 in words is "twenty-one trillion, eight hundred ninety-one billion, five hundred seventy-five million, two hundred fifty-five thousand, forty".