28213345 has 4 divisors (see below), whose sum is σ = 33856020. Its totient is φ = 22570672.

The previous prime is 28213343. The next prime is 28213373. The reversal of 28213345 is 54331282.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5058001 + 23155344 = 2249^2 + 4812^2 .

It is a cyclic number.

It is not a de Polignac number, because 28213345 - 2¹ = 28213343 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28213343) 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, 2821330 + ... + 2821339.

It is an arithmetic number, because the mean of its divisors is an integer number (8464005).

Almost surely, 2^28213345 is an apocalyptic number.

It is an amenable number.

28213345 is a deficient number, since it is larger than the sum of its proper divisors (5642675).

28213345 is an equidigital number, since it uses as much as digits as its factorization.

28213345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5642674.

The product of its digits is 5760, while the sum is 28.

The square root of 28213345 is about 5311.6235747651. The cubic root of 28213345 is about 304.4281860012.

The spelling of 28213345 in words is "twenty-eight million, two hundred thirteen thousand, three hundred forty-five".