21560522368 has 128 divisors (see below), whose sum is σ = 55880202240. Its totient is φ = 8034892800.

The previous prime is 21560522341. The next prime is 21560522443. The reversal of 21560522368 is 86322506512.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×21560522368² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21560522368.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 179133 + ... + 274243.

It is an arithmetic number, because the mean of its divisors is an integer number (436564080).

Almost surely, 2^21560522368 is an apocalyptic number.

21560522368 is a gapful number since it is divisible by the number (28) 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 21560522368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27940101120).

21560522368 is an abundant number, since it is smaller than the sum of its proper divisors (34319679872).

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

21560522368 is a wasteful number, since it uses less digits than its factorization.

21560522368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95166 (or 95154 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 40.

The spelling of 21560522368 in words is "twenty-one billion, five hundred sixty million, five hundred twenty-two thousand, three hundred sixty-eight".