21955302827640 has 768 divisors, whose sum is σ = 89589343334400. Its totient is φ = 4539993587712.

The previous prime is 21955302827611. The next prime is 21955302827641. The reversal of 21955302827640 is 4672820355912.

21955302827640 is a `hidden beast` number, since 2 + 1 + 9 + 5 + 530 + 28 + 27 + 64 + 0 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21955302827641) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 327271621 + ... + 327338699.

It is an arithmetic number, because the mean of its divisors is an integer number (116652790800).

It is a 1-persistent number, because it is pandigital, but 2⋅21955302827640 = 43910605655280 is not.

Almost surely, 2^{21955302827640} is an apocalyptic number.

21955302827640 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 21955302827640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44794671667200).

21955302827640 is an abundant number, since it is smaller than the sum of its proper divisors (67634040506760).

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

21955302827640 is a wasteful number, since it uses less digits than its factorization.

21955302827640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67316 (or 67309 counting only the distinct ones).

The product of its (nonzero) digits is 7257600, while the sum is 54.

The spelling of 21955302827640 in words is "twenty-one trillion, nine hundred fifty-five billion, three hundred two million, eight hundred twenty-seven thousand, six hundred forty".