21105641304 has 192 divisors, whose sum is σ = 66550947840. Its totient is φ = 5971553280.

The previous prime is 21105641303. The next prime is 21105641341. The reversal of 21105641304 is 40314650112.

It is a happy number.

21105641304 is a `hidden beast` number, since 2 + 1 + 10 + 5 + 641 + 3 + 0 + 4 = 666.

It is a super-2 number, since 2×21105641304² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21105641303) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1703757 + ... + 1716099.

It is an arithmetic number, because the mean of its divisors is an integer number (346619520).

Almost surely, 2^21105641304 is an apocalyptic number.

21105641304 is a gapful number since it is divisible by the number (24) 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 21105641304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33275473920).

21105641304 is an abundant number, since it is smaller than the sum of its proper divisors (45445306536).

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

21105641304 is a wasteful number, since it uses less digits than its factorization.

21105641304 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12510 (or 12503 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The spelling of 21105641304 in words is "twenty-one billion, one hundred five million, six hundred forty-one thousand, three hundred four".