28476721 has 8 divisors (see below), whose sum is σ = 35048384. Its totient is φ = 22530960.

The previous prime is 28476713. The next prime is 28476727. The reversal of 28476721 is 12767482.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28476721 - 2³ = 28476713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28476727) 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 7 ways as a sum of consecutive naturals, for example, 156375 + ... + 156556.

It is an arithmetic number, because the mean of its divisors is an integer number (4381048).

Almost surely, 2^28476721 is an apocalyptic number.

It is an amenable number.

28476721 is a deficient number, since it is larger than the sum of its proper divisors (6571663).

28476721 is a wasteful number, since it uses less digits than its factorization.

28476721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312951.

The product of its digits is 37632, while the sum is 37.

The square root of 28476721 is about 5336.3584025063. The cubic root of 28476721 is about 305.3725484307.

The spelling of 28476721 in words is "twenty-eight million, four hundred seventy-six thousand, seven hundred twenty-one".