21905795808260 has 288 divisors, whose sum is σ = 60132296835072. Its totient is φ = 6553146862080.

The previous prime is 21905795808251. The next prime is 21905795808331. The reversal of 21905795808260 is 6280859750912.

It is a Harshad number since it is a multiple of its sum of digits (62).

It is a junction number, because it is equal to n+sod(n) for n = 21905795808193 and 21905795808202.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 31191497 + ... + 31886063.

It is an arithmetic number, because the mean of its divisors is an integer number (208792697344).

Almost surely, 2^{21905795808260} is an apocalyptic number.

21905795808260 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 21905795808260, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30066148417536).

21905795808260 is an abundant number, since it is smaller than the sum of its proper divisors (38226501026812).

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

21905795808260 is a wasteful number, since it uses less digits than its factorization.

21905795808260 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 694683 (or 694668 counting only the distinct ones).

The product of its (nonzero) digits is 21772800, while the sum is 62.

The spelling of 21905795808260 in words is "twenty-one trillion, nine hundred five billion, seven hundred ninety-five million, eight hundred eight thousand, two hundred sixty".