28878971 has 16 divisors (see below), whose sum is σ = 33527520. Its totient is φ = 24583680.

The previous prime is 28878953. The next prime is 28878989. The reversal of 28878971 is 17987882.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (28878953) and next prime (28878989).

It is a de Polignac number, because none of the positive numbers 2^k-28878971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28878931) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 72545 + ... + 72941.

It is an arithmetic number, because the mean of its divisors is an integer number (2095470).

Almost surely, 2^28878971 is an apocalyptic number.

28878971 is a deficient number, since it is larger than the sum of its proper divisors (4648549).

28878971 is a wasteful number, since it uses less digits than its factorization.

28878971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 814.

The product of its digits is 451584, while the sum is 50.

The square root of 28878971 is about 5373.9157976284. The cubic root of 28878971 is about 306.8036849643.

The spelling of 28878971 in words is "twenty-eight million, eight hundred seventy-eight thousand, nine hundred seventy-one".