28550405 has 16 divisors (see below), whose sum is σ = 37035264. Its totient is φ = 21003840.

The previous prime is 28550393. The next prime is 28550447. The reversal of 28550405 is 50405582.

It is not a de Polignac number, because 28550405 - 2¹⁸ = 28288261 is a prime.

It is a Smith number, since the sum of its digits (29) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20852 + ... + 22178.

It is an arithmetic number, because the mean of its divisors is an integer number (2314704).

Almost surely, 2^28550405 is an apocalyptic number.

It is an amenable number.

28550405 is a deficient number, since it is larger than the sum of its proper divisors (8484859).

28550405 is a wasteful number, since it uses less digits than its factorization.

28550405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1676.

The product of its (nonzero) digits is 8000, while the sum is 29.

The square root of 28550405 is about 5343.2579013183. The cubic root of 28550405 is about 305.6357071398.

Adding to 28550405 its reverse (50405582), we get a palindrome (78955987).

The spelling of 28550405 in words is "twenty-eight million, five hundred fifty thousand, four hundred five".