28287977 has 4 divisors (see below), whose sum is σ = 28628880. Its totient is φ = 27947076.

The previous prime is 28287929. The next prime is 28288019. The reversal of 28287977 is 77978282.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 77978282 = 2 ⋅38989141.

It is a cyclic number.

It is not a de Polignac number, because 28287977 - 2⁶ = 28287913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28287377) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 170327 + ... + 170492.

It is an arithmetic number, because the mean of its divisors is an integer number (7157220).

Almost surely, 2^28287977 is an apocalyptic number.

It is an amenable number.

28287977 is a deficient number, since it is larger than the sum of its proper divisors (340903).

28287977 is an equidigital number, since it uses as much as digits as its factorization.

28287977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340902.

The product of its digits is 790272, while the sum is 50.

The square root of 28287977 is about 5318.6442821456. The cubic root of 28287977 is about 304.6963815443.

The spelling of 28287977 in words is "twenty-eight million, two hundred eighty-seven thousand, nine hundred seventy-seven".