28960785281 has 4 divisors (see below), whose sum is σ = 28962900564. Its totient is φ = 28958670000.

The previous prime is 28960785263. The next prime is 28960785289. The reversal of 28960785281 is 18258706982.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12330103681 + 16630681600 = 111041^2 + 128960^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28960785281 is a prime.

It is a super-2 number, since 2×28960785281² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28960785289) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1036970 + ... + 1064531.

It is an arithmetic number, because the mean of its divisors is an integer number (7240725141).

Almost surely, 2^28960785281 is an apocalyptic number.

It is an amenable number.

28960785281 is a deficient number, since it is larger than the sum of its proper divisors (2115283).

28960785281 is a wasteful number, since it uses less digits than its factorization.

28960785281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2115282.

The product of its (nonzero) digits is 3870720, while the sum is 56.

The spelling of 28960785281 in words is "twenty-eight billion, nine hundred sixty million, seven hundred eighty-five thousand, two hundred eighty-one".