28481905 has 4 divisors (see below), whose sum is σ = 34178292. Its totient is φ = 22785520.

The previous prime is 28481891. The next prime is 28481911. The reversal of 28481905 is 50918482.

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 8625969 + 19855936 = 2937^2 + 4456^2 .

It is not a de Polignac number, because 28481905 - 2¹³ = 28473713 is a prime.

It is a super-2 number, since 2×28481905² = 1622437824858050, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2848186 + ... + 2848195.

It is an arithmetic number, because the mean of its divisors is an integer number (8544573).

Almost surely, 2^28481905 is an apocalyptic number.

It is an amenable number.

28481905 is a deficient number, since it is larger than the sum of its proper divisors (5696387).

28481905 is an equidigital number, since it uses as much as digits as its factorization.

28481905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5696386.

The product of its (nonzero) digits is 23040, while the sum is 37.

The square root of 28481905 is about 5336.8441048994. The cubic root of 28481905 is about 305.3910776619.

It can be divided in two parts, 2848 and 1905, that added together give a triangular number (4753 = T₉₇).

The spelling of 28481905 in words is "twenty-eight million, four hundred eighty-one thousand, nine hundred five".