21004511244240 has 320 divisors, whose sum is σ = 67556418969600. Its totient is φ = 5395218554880.

The previous prime is 21004511244229. The next prime is 21004511244271. The reversal of 21004511244240 is 4244211540012.

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

It is a junction number, because it is equal to n+sod(n) for n = 21004511244198 and 21004511244207.

It is a congruent number.

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, 232020585 + ... + 232111095.

It is an arithmetic number, because the mean of its divisors is an integer number (211113809280).

Almost surely, 2^{21004511244240} is an apocalyptic number.

21004511244240 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 21004511244240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33778209484800).

21004511244240 is an abundant number, since it is smaller than the sum of its proper divisors (46551907725360).

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

21004511244240 is a wasteful number, since it uses less digits than its factorization.

21004511244240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90882 (or 90876 counting only the distinct ones).

The product of its (nonzero) digits is 10240, while the sum is 30.

Adding to 21004511244240 its reverse (4244211540012), we get a palindrome (25248722784252).

The spelling of 21004511244240 in words is "twenty-one trillion, four billion, five hundred eleven million, two hundred forty-four thousand, two hundred forty".