21024020644533 has 16 divisors (see below), whose sum is σ = 31147698487360. Its totient is φ = 14015563206768.

The previous prime is 21024020644531. The next prime is 21024020644541. The reversal of 21024020644533 is 33544602042012.

21024020644533 is a `hidden beast` number, since 2 + 1 + 0 + 2 + 4 + 0 + 2 + 0 + 644 + 5 + 3 + 3 = 666.

It is not a de Polignac number, because 21024020644533 - 2¹ = 21024020644531 is a prime.

It is a Duffinian number.

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 pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11658910 + ... + 13340847.

It is an arithmetic number, because the mean of its divisors is an integer number (1946731155460).

Almost surely, 2^{21024020644533} is an apocalyptic number.

It is an amenable number.

21024020644533 is a deficient number, since it is larger than the sum of its proper divisors (10123677842827).

21024020644533 is a wasteful number, since it uses less digits than its factorization.

21024020644533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25030913 (or 25030907 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 36.

Adding to 21024020644533 its reverse (33544602042012), we get a palindrome (54568622686545).

The spelling of 21024020644533 in words is "twenty-one trillion, twenty-four billion, twenty million, six hundred forty-four thousand, five hundred thirty-three".