28720766 has 8 divisors (see below), whose sum is σ = 43626720. Its totient is φ = 14178528.

The previous prime is 28720717. The next prime is 28720777. The reversal of 28720766 is 66702782.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 90731 + ... + 91046.

It is an arithmetic number, because the mean of its divisors is an integer number (5453340).

Almost surely, 2^28720766 is an apocalyptic number.

28720766 is a deficient number, since it is larger than the sum of its proper divisors (14905954).

28720766 is a wasteful number, since it uses less digits than its factorization.

28720766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181858.

The product of its (nonzero) digits is 56448, while the sum is 38.

The square root of 28720766 is about 5359.1758694784. The cubic root of 28720766 is about 306.2424140284.

The spelling of 28720766 in words is "twenty-eight million, seven hundred twenty thousand, seven hundred sixty-six".