28405265056281 has 27 divisors (see below), whose sum is σ = 41922485379541. Its totient is φ = 18533441481144.

The previous prime is 28405265056247. The next prime is 28405265056303. The reversal of 28405265056281 is 18265056250482.

The square root of 28405265056281 is 5329659.

It is a perfect power (a square), and thus also a powerful number.

28405265056281 is a `hidden beast` number, since 2 + 8 + 4 + 0 + 5 + 2 + 6 + 5 + 0 + 5 + 628 + 1 = 666.

It is not a de Polignac number, because 28405265056281 - 2³⁵ = 28370905317913 is a prime.

It is a super-2 number, since 2×28405265056281² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28405265056781) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 751463020 + ... + 751500818.

Almost surely, 2^{28405265056281} is an apocalyptic number.

28405265056281 is the 5329659-th square number.

28405265056281 is the 2664830-th centered octagonal number.

It is an amenable number.

28405265056281 is a deficient number, since it is larger than the sum of its proper divisors (13517220323260).

28405265056281 is an frugal number, since it uses more digits than its factorization.

28405265056281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75698 (or 37849 counting only the distinct ones).

The product of its (nonzero) digits is 9216000, while the sum is 54.

The spelling of 28405265056281 in words is "twenty-eight trillion, four hundred five billion, two hundred sixty-five million, fifty-six thousand, two hundred eighty-one".