28121773 has 4 divisors (see below), whose sum is σ = 28132380. Its totient is φ = 28111168.

The previous prime is 28121771. The next prime is 28121803. The reversal of 28121773 is 37712182.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 8779369 + 19342404 = 2963^2 + 4398^2 .

It is a cyclic number.

It is not a de Polignac number, because 28121773 - 2¹ = 28121771 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 (28121771) 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, 2643 + ... + 7951.

It is an arithmetic number, because the mean of its divisors is an integer number (7033095).

Almost surely, 2^28121773 is an apocalyptic number.

It is an amenable number.

28121773 is a deficient number, since it is larger than the sum of its proper divisors (10607).

28121773 is an equidigital number, since it uses as much as digits as its factorization.

28121773 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10606.

The product of its digits is 4704, while the sum is 31.

The square root of 28121773 is about 5302.9966056938. The cubic root of 28121773 is about 304.0984683615.

It can be divided in two parts, 28 and 121773, that added together give a square (121801 = 349²).

The spelling of 28121773 in words is "twenty-eight million, one hundred twenty-one thousand, seven hundred seventy-three".