28315261 has 8 divisors (see below), whose sum is σ = 30837240. Its totient is φ = 25842432.

The previous prime is 28315247. The next prime is 28315289. The reversal of 28315261 is 16251382.

It can be written as a sum of positive squares in 4 ways, for example, as 962361 + 27352900 = 981^2 + 5230^2 .

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 28315261 - 2⁵ = 28315229 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28315211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11080 + ... + 13393.

It is an arithmetic number, because the mean of its divisors is an integer number (3854655).

Almost surely, 2^28315261 is an apocalyptic number.

It is an amenable number.

28315261 is a deficient number, since it is larger than the sum of its proper divisors (2521979).

28315261 is a wasteful number, since it uses less digits than its factorization.

28315261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24575.

The product of its digits is 2880, while the sum is 28.

The square root of 28315261 is about 5321.2086033156. The cubic root of 28315261 is about 304.7943108371.

The spelling of 28315261 in words is "twenty-eight million, three hundred fifteen thousand, two hundred sixty-one".