21909135760 has 320 divisors, whose sum is σ = 57390612480. Its totient is φ = 7749181440.

The previous prime is 21909135751. The next prime is 21909135761. The reversal of 21909135760 is 6753190912.

It is a super-2 number, since 2×21909135760² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21909135761) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 172512817 + ... + 172512943.

It is an arithmetic number, because the mean of its divisors is an integer number (179345664).

Almost surely, 2^21909135760 is an apocalyptic number.

21909135760 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 21909135760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28695306240).

21909135760 is an abundant number, since it is smaller than the sum of its proper divisors (35481476720).

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

21909135760 is a wasteful number, since it uses less digits than its factorization.

21909135760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 306 (or 300 counting only the distinct ones).

The product of its (nonzero) digits is 102060, while the sum is 43.

The spelling of 21909135760 in words is "twenty-one billion, nine hundred nine million, one hundred thirty-five thousand, seven hundred sixty".