28207145 has 4 divisors (see below), whose sum is σ = 33848580. Its totient is φ = 22565712.

The previous prime is 28207141. The next prime is 28207159. The reversal of 28207145 is 54170282.

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 16152361 + 12054784 = 4019^2 + 3472^2 .

It is a cyclic number.

It is not a de Polignac number, because 28207145 - 2² = 28207141 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28207141) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2820710 + ... + 2820719.

It is an arithmetic number, because the mean of its divisors is an integer number (8462145).

Almost surely, 2^28207145 is an apocalyptic number.

It is an amenable number.

28207145 is a deficient number, since it is larger than the sum of its proper divisors (5641435).

28207145 is an equidigital number, since it uses as much as digits as its factorization.

28207145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5641434.

The product of its (nonzero) digits is 4480, while the sum is 29.

The square root of 28207145 is about 5311.0399170031. The cubic root of 28207145 is about 304.4058845805.

The spelling of 28207145 in words is "twenty-eight million, two hundred seven thousand, one hundred forty-five".