28252409 has 8 divisors (see below), whose sum is σ = 29293320. Its totient is φ = 27216000.

The previous prime is 28252397. The next prime is 28252447. The reversal of 28252409 is 90425282.

It can be written as a sum of positive squares in 4 ways, for example, as 12673600 + 15578809 = 3560^2 + 3947^2 .

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 28252409 - 2⁸ = 28252153 is a prime.

It is a super-2 number, since 2×28252409² = 1596397228606562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28252459) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16619 + ... + 18239.

It is an arithmetic number, because the mean of its divisors is an integer number (3661665).

Almost surely, 2^28252409 is an apocalyptic number.

28252409 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

28252409 is a deficient number, since it is larger than the sum of its proper divisors (1040911).

28252409 is a wasteful number, since it uses less digits than its factorization.

28252409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2251.

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 28252409 is about 5315.2995211935. The cubic root of 28252409 is about 304.5686242496.

The spelling of 28252409 in words is "twenty-eight million, two hundred fifty-two thousand, four hundred nine".