28125145 has 4 divisors (see below), whose sum is σ = 33750180. Its totient is φ = 22500112.

The previous prime is 28125127. The next prime is 28125169. The reversal of 28125145 is 54152182.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7139584 + 20985561 = 2672^2 + 4581^2 .

It is a cyclic number.

It is not a de Polignac number, because 28125145 - 2¹³ = 28116953 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2812510 + ... + 2812519.

It is an arithmetic number, because the mean of its divisors is an integer number (8437545).

Almost surely, 2^28125145 is an apocalyptic number.

It is an amenable number.

28125145 is a deficient number, since it is larger than the sum of its proper divisors (5625035).

28125145 is an equidigital number, since it uses as much as digits as its factorization.

28125145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5625034.

The product of its digits is 3200, while the sum is 28.

The square root of 28125145 is about 5303.3145296126. The cubic root of 28125145 is about 304.1106223966.

The spelling of 28125145 in words is "twenty-eight million, one hundred twenty-five thousand, one hundred forty-five".