28308305 has 8 divisors (see below), whose sum is σ = 34435752. Its totient is φ = 22336128.

The previous prime is 28308299. The next prime is 28308311. The reversal of 28308305 is 50380382.

It is an interprime number because it is at equal distance from previous prime (28308299) and next prime (28308311).

It can be written as a sum of positive squares in 4 ways, for example, as 861184 + 27447121 = 928^2 + 5239^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28308305 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38414 + ... + 39143.

It is an arithmetic number, because the mean of its divisors is an integer number (4304469).

Almost surely, 2^28308305 is an apocalyptic number.

It is an amenable number.

28308305 is a deficient number, since it is larger than the sum of its proper divisors (6127447).

28308305 is an equidigital number, since it uses as much as digits as its factorization.

28308305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77635.

The product of its (nonzero) digits is 5760, while the sum is 29.

The square root of 28308305 is about 5320.5549522583. The cubic root of 28308305 is about 304.7693499410.

Adding to 28308305 its reverse (50380382), we get a palindrome (78688687).

The spelling of 28308305 in words is "twenty-eight million, three hundred eight thousand, three hundred five".