21050253240720 has 320 divisors, whose sum is σ = 75193475309568. Its totient is φ = 4823626752000.

The previous prime is 21050253240707. The next prime is 21050253240743. The reversal of 21050253240720 is 2704235205012.

It is a super-3 number, since 3×21050253240720³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 528280 + ... + 6509960.

Almost surely, 2^{21050253240720} is an apocalyptic number.

21050253240720 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 21050253240720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37596737654784).

21050253240720 is an abundant number, since it is smaller than the sum of its proper divisors (54143222068848).

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

21050253240720 is a wasteful number, since it uses less digits than its factorization.

21050253240720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5981782 (or 5981776 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 33.

Adding to 21050253240720 its reverse (2704235205012), we get a palindrome (23754488445732).

The spelling of 21050253240720 in words is "twenty-one trillion, fifty billion, two hundred fifty-three million, two hundred forty thousand, seven hundred twenty".