21024425323440 has 720 divisors, whose sum is σ = 89629295277600. Its totient is φ = 4367356600320.

The previous prime is 21024425323411. The next prime is 21024425323453. The reversal of 21024425323440 is 4432352442012.

21024425323440 is a `hidden beast` number, since 2 + 10 + 2 + 4 + 42 + 532 + 34 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

It is a super-2 number, since 2×21024425323440² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21024425323395 and 21024425323404.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 1687753692 + ... + 1687766148.

It is an arithmetic number, because the mean of its divisors is an integer number (124485132330).

Almost surely, 2^{21024425323440} is an apocalyptic number.

21024425323440 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 21024425323440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44814647638800).

21024425323440 is an abundant number, since it is smaller than the sum of its proper divisors (68604869954160).

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

21024425323440 is a wasteful number, since it uses less digits than its factorization.

21024425323440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16850 (or 16834 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 36.

Adding to 21024425323440 its reverse (4432352442012), we get a palindrome (25456777765452).

The spelling of 21024425323440 in words is "twenty-one trillion, twenty-four billion, four hundred twenty-five million, three hundred twenty-three thousand, four hundred forty".