28881805 has 12 divisors (see below), whose sum is σ = 36580572. Its totient is φ = 21888000.

The previous prime is 28881803. The next prime is 28881833. The reversal of 28881805 is 50818882.

It can be written as a sum of positive squares in 2 ways, for example, as 17952169 + 10929636 = 4237^2 + 3306^2 .

It is not a de Polignac number, because 28881805 - 2¹ = 28881803 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28881803) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6196 + ... + 9805.

It is an arithmetic number, because the mean of its divisors is an integer number (3048381).

Almost surely, 2^28881805 is an apocalyptic number.

It is an amenable number.

28881805 is a deficient number, since it is larger than the sum of its proper divisors (7698767).

28881805 is a wasteful number, since it uses less digits than its factorization.

28881805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16044 (or 16025 counting only the distinct ones).

The product of its (nonzero) digits is 40960, while the sum is 40.

The square root of 28881805 is about 5374.1794722543. The cubic root of 28881805 is about 306.8137205620.

The spelling of 28881805 in words is "twenty-eight million, eight hundred eighty-one thousand, eight hundred five".