21000343102440 has 128 divisors (see below), whose sum is σ = 67877123005440. Its totient is φ = 5167040126976.

The previous prime is 21000343102399. The next prime is 21000343102447. The reversal of 21000343102440 is 4420134300012.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 21000343102440.

It is not an unprimeable number, because it can be changed into a prime (21000343102447) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 584649 + ... + 6507111.

It is an arithmetic number, because the mean of its divisors is an integer number (530290023480).

Almost surely, 2^{21000343102440} is an apocalyptic number.

21000343102440 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 21000343102440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33938561502720).

21000343102440 is an abundant number, since it is smaller than the sum of its proper divisors (46876779903000).

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

21000343102440 is a wasteful number, since it uses less digits than its factorization.

21000343102440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5924763 (or 5924759 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 24.

Adding to 21000343102440 its reverse (4420134300012), we get a palindrome (25420477402452).

The spelling of 21000343102440 in words is "twenty-one trillion, three hundred forty-three million, one hundred two thousand, four hundred forty".