28221736756 has 12 divisors (see below), whose sum is σ = 49413085092. Its totient is φ = 14103712448.

The previous prime is 28221736727. The next prime is 28221736783. The reversal of 28221736756 is 65763712282.

It can be written as a sum of positive squares in 2 ways, for example, as 19200536356 + 9021200400 = 138566^2 + 94980^2 .

It is a super-2 number, since 2×28221736756² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1780105 + ... + 1795888.

It is an arithmetic number, because the mean of its divisors is an integer number (4117757091).

Almost surely, 2^28221736756 is an apocalyptic number.

It is an amenable number.

28221736756 is a deficient number, since it is larger than the sum of its proper divisors (21191348336).

28221736756 is a wasteful number, since it uses less digits than its factorization.

28221736756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3577970 (or 3577968 counting only the distinct ones).

The product of its digits is 1693440, while the sum is 49.

The spelling of 28221736756 in words is "twenty-eight billion, two hundred twenty-one million, seven hundred thirty-six thousand, seven hundred fifty-six".