21055433660 has 48 divisors (see below), whose sum is σ = 44607561600. Its totient is φ = 8347869504.

The previous prime is 21055433653. The next prime is 21055433671. The reversal of 21055433660 is 6633455012.

It is a super-2 number, since 2×21055433660² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21055433660.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1781651 + ... + 1793429.

It is an arithmetic number, because the mean of its divisors is an integer number (929324200).

Almost surely, 2^21055433660 is an apocalyptic number.

21055433660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21055433660 is an abundant number, since it is smaller than the sum of its proper divisors (23552127940).

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

21055433660 is a wasteful number, since it uses less digits than its factorization.

21055433660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12570 (or 12568 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 35.

Adding to 21055433660 its reverse (6633455012), we get a palindrome (27688888672).

The spelling of 21055433660 in words is "twenty-one billion, fifty-five million, four hundred thirty-three thousand, six hundred sixty".