28821173 has 4 divisors (see below), whose sum is σ = 28980588. Its totient is φ = 28661760.

The previous prime is 28821161. The next prime is 28821181. The reversal of 28821173 is 37112882.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 37112882 = 2 ⋅18556441.

It can be written as a sum of positive squares in 2 ways, for example, as 7963684 + 20857489 = 2822^2 + 4567^2 .

It is a cyclic number.

It is not a de Polignac number, because 28821173 - 2⁶ = 28821109 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28821673) 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, 79436 + ... + 79797.

It is an arithmetic number, because the mean of its divisors is an integer number (7245147).

Almost surely, 2^28821173 is an apocalyptic number.

It is an amenable number.

28821173 is a deficient number, since it is larger than the sum of its proper divisors (159415).

28821173 is a wasteful number, since it uses less digits than its factorization.

28821173 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159414.

The product of its digits is 5376, while the sum is 32.

The square root of 28821173 is about 5368.5354613712. The cubic root of 28821173 is about 306.5988706202.

The spelling of 28821173 in words is "twenty-eight million, eight hundred twenty-one thousand, one hundred seventy-three".