28025773281 has 135 divisors (see below), whose sum is σ = 49118909763. Its totient is φ = 15910551360.

The previous prime is 28025773261. The next prime is 28025773289. The reversal of 28025773281 is 18237752082.

The square root of 28025773281 is 167409.

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

28025773281 is a `hidden beast` number, since 280 + 25 + 7 + 73 + 281 = 666.

It can be written as a sum of positive squares in only one way, i.e., 5381542881 + 22644230400 = 73359^2 + 150480^2 .

It is not a de Polignac number, because 28025773281 - 2⁹ = 28025772769 is a prime.

It is a super-2 number, since 2×28025773281² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28025773289) 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 134 ways as a sum of consecutive naturals, for example, 314896285 + ... + 314896373.

Almost surely, 2^28025773281 is an apocalyptic number.

28025773281 is the 167409-th square number.

28025773281 is the 83705-th centered octagonal number.

It is an amenable number.

28025773281 is a deficient number, since it is larger than the sum of its proper divisors (21093136482).

28025773281 is an equidigital number, since it uses as much as digits as its factorization.

28025773281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 250 (or 122 counting only the distinct ones).

The product of its (nonzero) digits is 376320, while the sum is 45.

The spelling of 28025773281 in words is "twenty-eight billion, twenty-five million, seven hundred seventy-three thousand, two hundred eighty-one".