28222813 has 4 divisors (see below), whose sum is σ = 28237468. Its totient is φ = 28208160.

The previous prime is 28222783. The next prime is 28222819. The reversal of 28222813 is 31822282.

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 15705369 + 12517444 = 3963^2 + 3538^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28222813 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 (28222819) 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, 3906 + ... + 8467.

It is an arithmetic number, because the mean of its divisors is an integer number (7059367).

Almost surely, 2^28222813 is an apocalyptic number.

It is an amenable number.

28222813 is a deficient number, since it is larger than the sum of its proper divisors (14655).

28222813 is a wasteful number, since it uses less digits than its factorization.

28222813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14654.

The product of its digits is 3072, while the sum is 28.

The square root of 28222813 is about 5312.5147529207. The cubic root of 28222813 is about 304.4622361253.

The spelling of 28222813 in words is "twenty-eight million, two hundred twenty-two thousand, eight hundred thirteen".