28362581 has 4 divisors (see below), whose sum is σ = 30544332. Its totient is φ = 26180832.

The previous prime is 28362571. The next prime is 28362599. The reversal of 28362581 is 18526382.

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 9579025 + 18783556 = 3095^2 + 4334^2 .

It is a cyclic number.

It is not a de Polignac number, because 28362581 - 2¹⁸ = 28100437 is a prime.

It is a super-2 number, since 2×28362581² = 1608872001963122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28362571) by changing a digit.

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, 1090856 + ... + 1090881.

It is an arithmetic number, because the mean of its divisors is an integer number (7636083).

Almost surely, 2^28362581 is an apocalyptic number.

It is an amenable number.

28362581 is a deficient number, since it is larger than the sum of its proper divisors (2181751).

28362581 is a wasteful number, since it uses less digits than its factorization.

28362581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2181750.

The product of its digits is 23040, while the sum is 35.

The square root of 28362581 is about 5325.6531054886. The cubic root of 28362581 is about 304.9640054271.

The spelling of 28362581 in words is "twenty-eight million, three hundred sixty-two thousand, five hundred eighty-one".