28433276581 has 4 divisors (see below), whose sum is σ = 28433968812. Its totient is φ = 28432584352.

The previous prime is 28433276569. The next prime is 28433276623. The reversal of 28433276581 is 18567233482.

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 12540640225 + 15892636356 = 111985^2 + 126066^2 .

It is a cyclic number.

It is not a de Polignac number, because 28433276581 - 2⁵ = 28433276549 is a prime.

It is a super-2 number, since 2×28433276581² (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 (28433276561) 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 3 ways as a sum of consecutive naturals, for example, 280336 + ... + 368041.

It is an arithmetic number, because the mean of its divisors is an integer number (7108492203).

Almost surely, 2^28433276581 is an apocalyptic number.

It is an amenable number.

28433276581 is a deficient number, since it is larger than the sum of its proper divisors (692231).

28433276581 is an equidigital number, since it uses as much as digits as its factorization.

28433276581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 692230.

The product of its digits is 1935360, while the sum is 49.

The spelling of 28433276581 in words is "twenty-eight billion, four hundred thirty-three million, two hundred seventy-six thousand, five hundred eighty-one".