28878973 has 4 divisors (see below), whose sum is σ = 28924668. Its totient is φ = 28833280.

The previous prime is 28878953. The next prime is 28878989. The reversal of 28878973 is 37987882.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 37987882 = 2 ⋅18993941.

It can be written as a sum of positive squares in 2 ways, for example, as 23299929 + 5579044 = 4827^2 + 2362^2 .

It is a cyclic number.

It is not a de Polignac number, because 28878973 - 2¹³ = 28870781 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28878973.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28878923) 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, 21886 + ... + 23167.

It is an arithmetic number, because the mean of its divisors is an integer number (7231167).

Almost surely, 2^28878973 is an apocalyptic number.

It is an amenable number.

28878973 is a deficient number, since it is larger than the sum of its proper divisors (45695).

28878973 is an equidigital number, since it uses as much as digits as its factorization.

28878973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45694.

The product of its digits is 1354752, while the sum is 52.

The square root of 28878973 is about 5373.9159837124. The cubic root of 28878973 is about 306.8036920468.

The spelling of 28878973 in words is "twenty-eight million, eight hundred seventy-eight thousand, nine hundred seventy-three".