28991044 has 6 divisors (see below), whose sum is σ = 50734334. Its totient is φ = 14495520.

The previous prime is 28991041. The next prime is 28991071. The reversal of 28991044 is 44019982.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 26625600 + 2365444 = 5160^2 + 1538^2 .

It is a junction number, because it is equal to n+sod(n) for n = 28990994 and 28991012.

It is not an unprimeable number, because it can be changed into a prime (28991041) 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 as a sum of consecutive naturals, namely, 3623877 + ... + 3623884.

Almost surely, 2^28991044 is an apocalyptic number.

It is an amenable number.

28991044 is a deficient number, since it is larger than the sum of its proper divisors (21743290).

28991044 is a wasteful number, since it uses less digits than its factorization.

28991044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7247765 (or 7247763 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 28991044 is about 5384.3331991993. Note that the first 3 decimals coincide. The cubic root of 28991044 is about 307.2000521059.

The spelling of 28991044 in words is "twenty-eight million, nine hundred ninety-one thousand, forty-four".