28890039 has 4 divisors (see below), whose sum is σ = 38520056. Its totient is φ = 19260024.

The previous prime is 28890031. The next prime is 28890053. The reversal of 28890039 is 93009882.

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

It is not a de Polignac number, because 28890039 - 2³ = 28890031 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28889979 and 28890006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28890031) 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, 4815004 + ... + 4815009.

It is an arithmetic number, because the mean of its divisors is an integer number (9630014).

Almost surely, 2^28890039 is an apocalyptic number.

28890039 is a deficient number, since it is larger than the sum of its proper divisors (9630017).

28890039 is an equidigital number, since it uses as much as digits as its factorization.

28890039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9630016.

The product of its (nonzero) digits is 31104, while the sum is 39.

The square root of 28890039 is about 5374.9454880957. The cubic root of 28890039 is about 306.8428746048.

The spelling of 28890039 in words is "twenty-eight million, eight hundred ninety thousand, thirty-nine".