28661805 has 24 divisors (see below), whose sum is σ = 49840128. Its totient is φ = 15237216.

The previous prime is 28661803. The next prime is 28661807. The reversal of 28661805 is 50816682.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (28661803) and next prime (28661807).

It is not a de Polignac number, because 28661805 - 2¹ = 28661803 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 28661805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28661803) 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 23 ways as a sum of consecutive naturals, for example, 16404 + ... + 18066.

It is an arithmetic number, because the mean of its divisors is an integer number (2076672).

Almost surely, 2^28661805 is an apocalyptic number.

It is an amenable number.

28661805 is a deficient number, since it is larger than the sum of its proper divisors (21178323).

28661805 is a wasteful number, since it uses less digits than its factorization.

28661805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2057 (or 2054 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 28661805 is about 5353.6721042664. The cubic root of 28661805 is about 306.0327082812.

The spelling of 28661805 in words is "twenty-eight million, six hundred sixty-one thousand, eight hundred five".