28399977 has 10 divisors (see below), whose sum is σ = 42424778. Its totient is φ = 18933264.

The previous prime is 28399949. The next prime is 28399991. The reversal of 28399977 is 77999382.

It can be written as a sum of positive squares in only one way, i.e., 27154521 + 1245456 = 5211^2 + 1116^2 .

It is not a de Polignac number, because 28399977 - 2⁷ = 28399849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28399907) 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 9 ways as a sum of consecutive naturals, for example, 175228 + ... + 175389.

Almost surely, 2^28399977 is an apocalyptic number.

28399977 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

28399977 is a deficient number, since it is larger than the sum of its proper divisors (14024801).

28399977 is an equidigital number, since it uses as much as digits as its factorization.

28399977 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 350629 (or 350620 counting only the distinct ones).

The product of its digits is 1714608, while the sum is 54.

The square root of 28399977 is about 5329.1628798527. The cubic root of 28399977 is about 305.0979780179.

The spelling of 28399977 in words is "twenty-eight million, three hundred ninety-nine thousand, nine hundred seventy-seven".