28208545 has 4 divisors (see below), whose sum is σ = 33850260. Its totient is φ = 22566832.

The previous prime is 28208539. The next prime is 28208563. The reversal of 28208545 is 54580282.

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 6974881 + 21233664 = 2641^2 + 4608^2 .

It is a cyclic number.

It is not a de Polignac number, because 28208545 - 2¹⁷ = 28077473 is a prime.

It is a super-2 number, since 2×28208545² = 1591444022034050, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28208545.

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, 2820850 + ... + 2820859.

It is an arithmetic number, because the mean of its divisors is an integer number (8462565).

Almost surely, 2^28208545 is an apocalyptic number.

It is an amenable number.

28208545 is a deficient number, since it is larger than the sum of its proper divisors (5641715).

28208545 is an equidigital number, since it uses as much as digits as its factorization.

28208545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5641714.

The product of its (nonzero) digits is 25600, while the sum is 34.

The square root of 28208545 is about 5311.1717162976. The cubic root of 28208545 is about 304.4109206708.

The spelling of 28208545 in words is "twenty-eight million, two hundred eight thousand, five hundred forty-five".