28185481 has 3 divisors (see below), whose sum is σ = 28190791. Its totient is φ = 28180172.

The previous prime is 28185467. The next prime is 28185503. The reversal of 28185481 is 18458182.

It is a happy number.

The square root of 28185481 is 5309.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 18458182 = 2 ⋅9229091.

It can be written as a sum of positive squares in only one way, i.e., 95481 + 28090000 = 309^2 + 5300^2 .

It is not a de Polignac number, because 28185481 - 2⁹ = 28184969 is a prime.

It is a super-2 number, since 2×28185481² = 1588842678402722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28185481.

It is not an unprimeable number, because it can be changed into a prime (28185401) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2655 + ... + 7963.

Almost surely, 2^28185481 is an apocalyptic number.

28185481 is the 5309-th square number.

28185481 is the 2655-th centered octagonal number.

It is an amenable number.

28185481 is a deficient number, since it is larger than the sum of its proper divisors (5310).

28185481 is an frugal number, since it uses more digits than its factorization.

28185481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10618 (or 5309 counting only the distinct ones).

The product of its digits is 20480, while the sum is 37.

The cubic root of 28185481 is about 304.3279334313.

The spelling of 28185481 in words is "twenty-eight million, one hundred eighty-five thousand, four hundred eighty-one".