28255502581 has 8 divisors (see below), whose sum is σ = 28286740440. Its totient is φ = 28224284928.

The previous prime is 28255502563. The next prime is 28255502591. The reversal of 28255502581 is 18520555282.

It can be written as a sum of positive squares in 4 ways, for example, as 5656393681 + 22599108900 = 75209^2 + 150330^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28255502581 - 2¹⁹ = 28254978293 is a prime.

It is a super-2 number, since 2×28255502581² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28255502591) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5720745 + ... + 5725681.

It is an arithmetic number, because the mean of its divisors is an integer number (3535842555).

Almost surely, 2^28255502581 is an apocalyptic number.

It is an amenable number.

28255502581 is a deficient number, since it is larger than the sum of its proper divisors (31237859).

28255502581 is a wasteful number, since it uses less digits than its factorization.

28255502581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10103.

The product of its (nonzero) digits is 320000, while the sum is 43.

The spelling of 28255502581 in words is "twenty-eight billion, two hundred fifty-five million, five hundred two thousand, five hundred eighty-one".