21026026560 has 448 divisors, whose sum is σ = 84612870144. Its totient is φ = 4296499200.

The previous prime is 21026026537. The next prime is 21026026577. The reversal of 21026026560 is 6562062012.

It is a tau number, because it is divible by the number of its divisors (448).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4506789 + ... + 4511451.

Almost surely, 2^21026026560 is an apocalyptic number.

21026026560 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 21026026560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42306435072).

21026026560 is an abundant number, since it is smaller than the sum of its proper divisors (63586843584).

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

21026026560 is a wasteful number, since it uses less digits than its factorization.

21026026560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4762 (or 4752 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

Adding to 21026026560 its reverse (6562062012), we get a palindrome (27588088572).

The spelling of 21026026560 in words is "twenty-one billion, twenty-six million, twenty-six thousand, five hundred sixty".