28724481 has 6 divisors (see below), whose sum is σ = 41490930. Its totient is φ = 19149648.

The previous prime is 28724467. The next prime is 28724491. The reversal of 28724481 is 18442782.

It can be written as a sum of positive squares in only one way, i.e., 15872256 + 12852225 = 3984^2 + 3585^2 .

It is not a de Polignac number, because 28724481 - 2⁹ = 28723969 is a prime.

It is a super-2 number, since 2×28724481² = 1650191617438722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28724461) 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, 1595796 + ... + 1595813.

It is an arithmetic number, because the mean of its divisors is an integer number (6915155).

Almost surely, 2^28724481 is an apocalyptic number.

It is an amenable number.

28724481 is a deficient number, since it is larger than the sum of its proper divisors (12766449).

28724481 is a wasteful number, since it uses less digits than its factorization.

28724481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3191615 (or 3191612 counting only the distinct ones).

The product of its digits is 28672, while the sum is 36.

The square root of 28724481 is about 5359.5224600705. The cubic root of 28724481 is about 306.2556175007.

The spelling of 28724481 in words is "twenty-eight million, seven hundred twenty-four thousand, four hundred eighty-one".