28723787 has 4 divisors (see below), whose sum is σ = 28736760. Its totient is φ = 28710816.

The previous prime is 28723781. The next prime is 28723811. The reversal of 28723787 is 78732782.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28723787 - 2²⁰ = 27675211 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28723781) 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 in 3 ways as a sum of consecutive naturals, for example, 2237 + ... + 7902.

It is an arithmetic number, because the mean of its divisors is an integer number (7184190).

Almost surely, 2^28723787 is an apocalyptic number.

28723787 is a deficient number, since it is larger than the sum of its proper divisors (12973).

28723787 is a wasteful number, since it uses less digits than its factorization.

28723787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12972.

The product of its digits is 263424, while the sum is 44.

The square root of 28723787 is about 5359.4577151051. The cubic root of 28723787 is about 306.2531510435.

The spelling of 28723787 in words is "twenty-eight million, seven hundred twenty-three thousand, seven hundred eighty-seven".