28409375 has 12 divisors (see below), whose sum is σ = 35513352. Its totient is φ = 22725000.

The previous prime is 28409371. The next prime is 28409411. The reversal of 28409375 is 57390482.

It is not a de Polignac number, because 28409375 - 2² = 28409371 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 (28409371) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1421 + ... + 7670.

It is an arithmetic number, because the mean of its divisors is an integer number (2959446).

Almost surely, 2^28409375 is an apocalyptic number.

28409375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

28409375 is a deficient number, since it is larger than the sum of its proper divisors (7103977).

28409375 is an frugal number, since it uses more digits than its factorization.

28409375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9116 (or 9096 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 38.

The square root of 28409375 is about 5330.0445589132. The cubic root of 28409375 is about 305.1316282162.

The spelling of 28409375 in words is "twenty-eight million, four hundred nine thousand, three hundred seventy-five".