28905145 has 4 divisors (see below), whose sum is σ = 34686180. Its totient is φ = 23124112.

The previous prime is 28905143. The next prime is 28905167. The reversal of 28905145 is 54150982.

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 21353641 + 7551504 = 4621^2 + 2748^2 .

It is a cyclic number.

It is not a de Polignac number, because 28905145 - 2¹ = 28905143 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28905145.

It is not an unprimeable number, because it can be changed into a prime (28905143) 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, 2890510 + ... + 2890519.

It is an arithmetic number, because the mean of its divisors is an integer number (8671545).

Almost surely, 2^28905145 is an apocalyptic number.

It is an amenable number.

28905145 is a deficient number, since it is larger than the sum of its proper divisors (5781035).

28905145 is an equidigital number, since it uses as much as digits as its factorization.

28905145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5781034.

The product of its (nonzero) digits is 14400, while the sum is 34.

The square root of 28905145 is about 5376.3505280069. The cubic root of 28905145 is about 306.8963458701.

The spelling of 28905145 in words is "twenty-eight million, nine hundred five thousand, one hundred forty-five".