21263326560 has 432 divisors, whose sum is σ = 87139608192. Its totient is φ = 4702924800.

The previous prime is 21263326549. The next prime is 21263326571. The reversal of 21263326560 is 6562336212.

21263326560 is a `hidden beast` number, since 2 + 1 + 2 + 63 + 32 + 6 + 560 = 666.

It is an interprime number because it is at equal distance from previous prime (21263326549) and next prime (21263326571).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

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 71 ways as a sum of consecutive naturals, for example, 2182500 + ... + 2192220.

It is an arithmetic number, because the mean of its divisors is an integer number (201712056).

Almost surely, 2^21263326560 is an apocalyptic number.

21263326560 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 21263326560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43569804096).

21263326560 is an abundant number, since it is smaller than the sum of its proper divisors (65876281632).

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

21263326560 is a wasteful number, since it uses less digits than its factorization.

21263326560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9787 (or 9769 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 36.

The spelling of 21263326560 in words is "twenty-one billion, two hundred sixty-three million, three hundred twenty-six thousand, five hundred sixty".