28878890 has 16 divisors (see below), whose sum is σ = 52285608. Its totient is φ = 11484096.

The previous prime is 28878881. The next prime is 28878893. The reversal of 28878890 is 9887882.

It can be written as a sum of positive squares in 4 ways, for example, as 22743361 + 6135529 = 4769^2 + 2477^2 .

It is not an unprimeable number, because it can be changed into a prime (28878893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6617 + ... + 10076.

Almost surely, 2^28878890 is an apocalyptic number.

28878890 is a deficient number, since it is larger than the sum of its proper divisors (23406718).

28878890 is a wasteful number, since it uses less digits than its factorization.

28878890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16873.

The product of its (nonzero) digits is 516096, while the sum is 50.

The square root of 28878890 is about 5373.9082612192. The cubic root of 28878890 is about 306.8033981221.

The spelling of 28878890 in words is "twenty-eight million, eight hundred seventy-eight thousand, eight hundred ninety".