21020008911440 has 320 divisors, whose sum is σ = 61066080092160. Its totient is φ = 6537156433920.

The previous prime is 21020008911437. The next prime is 21020008911449. The reversal of 21020008911440 is 4411980002012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21020008911397 and 21020008911406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020008911449) by changing a digit.

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, 7596676937 + ... + 7596679703.

It is an arithmetic number, because the mean of its divisors is an integer number (190831500288).

Almost surely, 2^{21020008911440} is an apocalyptic number.

21020008911440 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 21020008911440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30533040046080).

21020008911440 is an abundant number, since it is smaller than the sum of its proper divisors (40046071180720).

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

21020008911440 is a wasteful number, since it uses less digits than its factorization.

21020008911440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5090 (or 5084 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 32.

Adding to 21020008911440 its reverse (4411980002012), we get a palindrome (25431988913452).

The spelling of 21020008911440 in words is "twenty-one trillion, twenty billion, eight million, nine hundred eleven thousand, four hundred forty".