21024020644532 has 12 divisors (see below), whose sum is σ = 36796831181796. Its totient is φ = 10510640306880.

The previous prime is 21024020644531. The next prime is 21024020644541. The reversal of 21024020644532 is 23544602042012.

It can be written as a sum of positive squares in 2 ways, for example, as 13105008167056 + 7919012477476 = 3620084^2 + 2814074^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21024020644492 and 21024020644501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21024020644531) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 342469319 + ... + 342530702.

It is an arithmetic number, because the mean of its divisors is an integer number (3066402598483).

Almost surely, 2^{21024020644532} is an apocalyptic number.

It is an amenable number.

21024020644532 is a deficient number, since it is larger than the sum of its proper divisors (15772810537264).

21024020644532 is a wasteful number, since it uses less digits than its factorization.

21024020644532 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 685007698 (or 685007696 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 35.

Adding to 21024020644532 its reverse (23544602042012), we get a palindrome (44568622686544).

The spelling of 21024020644532 in words is "twenty-one trillion, twenty-four billion, twenty million, six hundred forty-four thousand, five hundred thirty-two".