28077139 has 4 divisors (see below), whose sum is σ = 28096024. Its totient is φ = 28058256.

The previous prime is 28077131. The next prime is 28077173. The reversal of 28077139 is 93177082.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93177082 = 2 ⋅46588541.

It is a cyclic number.

It is not a de Polignac number, because 28077139 - 2³ = 28077131 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28077098 and 28077107.

It is not an unprimeable number, because it can be changed into a prime (28077131) 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, 7002 + ... + 10255.

It is an arithmetic number, because the mean of its divisors is an integer number (7024006).

Almost surely, 2^28077139 is an apocalyptic number.

28077139 is a deficient number, since it is larger than the sum of its proper divisors (18885).

28077139 is a wasteful number, since it uses less digits than its factorization.

28077139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18884.

The product of its (nonzero) digits is 21168, while the sum is 37.

The square root of 28077139 is about 5298.7865592039. The cubic root of 28077139 is about 303.9374979712.

The spelling of 28077139 in words is "twenty-eight million, seventy-seven thousand, one hundred thirty-nine".