28509121 has 8 divisors (see below), whose sum is σ = 29802240. Its totient is φ = 27220512.

The previous prime is 28509097. The next prime is 28509133. The reversal of 28509121 is 12190582.

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 28509121 - 2¹⁵ = 28476353 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28509121.

It is not an unprimeable number, because it can be changed into a prime (28509521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23301 + ... + 24493.

It is an arithmetic number, because the mean of its divisors is an integer number (3725280).

Almost surely, 2^28509121 is an apocalyptic number.

It is an amenable number.

28509121 is a deficient number, since it is larger than the sum of its proper divisors (1293119).

28509121 is a wasteful number, since it uses less digits than its factorization.

28509121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2255.

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 28509121 is about 5339.3933175970. The cubic root of 28509121 is about 305.4883192568.

The spelling of 28509121 in words is "twenty-eight million, five hundred nine thousand, one hundred twenty-one".