28705597 has 4 divisors (see below), whose sum is σ = 29631616. Its totient is φ = 27779580.

The previous prime is 28705591. The next prime is 28705601. The reversal of 28705597 is 79550782.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 79550782 = 2 ⋅39775391.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28705597 is a prime.

It is a super-2 number, since 2×28705597² = 1648022598252818, which 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 (28705591) 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 3 ways as a sum of consecutive naturals, for example, 462963 + ... + 463024.

It is an arithmetic number, because the mean of its divisors is an integer number (7407904).

Almost surely, 2^28705597 is an apocalyptic number.

It is an amenable number.

28705597 is a deficient number, since it is larger than the sum of its proper divisors (926019).

28705597 is an equidigital number, since it uses as much as digits as its factorization.

28705597 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 926018.

The product of its (nonzero) digits is 176400, while the sum is 43.

The square root of 28705597 is about 5357.7604463059. The cubic root of 28705597 is about 306.1884901040.

The spelling of 28705597 in words is "twenty-eight million, seven hundred five thousand, five hundred ninety-seven".