28185649 has 6 divisors (see below), whose sum is σ = 29464946. Its totient is φ = 26959680.

The previous prime is 28185631. The next prime is 28185659. The reversal of 28185649 is 94658182.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 24453025 + 3732624 = 4945^2 + 1932^2 .

It is not a de Polignac number, because 28185649 - 2⁵ = 28185617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28185659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 26112 + ... + 27169.

Almost surely, 2^28185649 is an apocalyptic number.

It is an amenable number.

28185649 is a deficient number, since it is larger than the sum of its proper divisors (1279297).

28185649 is an equidigital number, since it uses as much as digits as its factorization.

28185649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53327 (or 53304 counting only the distinct ones).

The product of its digits is 138240, while the sum is 43.

The square root of 28185649 is about 5309.0158221652. The cubic root of 28185649 is about 304.3285380805.

The spelling of 28185649 in words is "twenty-eight million, one hundred eighty-five thousand, six hundred forty-nine".