28130213 has 4 divisors (see below), whose sum is σ = 28784448. Its totient is φ = 27475980.

The previous prime is 28130209. The next prime is 28130231. The reversal of 28130213 is 31203182.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 31203182 = 2 ⋅15601591.

It is a cyclic number.

It is not a de Polignac number, because 28130213 - 2² = 28130209 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 (28130273) 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, 327053 + ... + 327138.

It is an arithmetic number, because the mean of its divisors is an integer number (7196112).

Almost surely, 2^28130213 is an apocalyptic number.

It is an amenable number.

28130213 is a deficient number, since it is larger than the sum of its proper divisors (654235).

28130213 is an equidigital number, since it uses as much as digits as its factorization.

28130213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 654234.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 28130213 is about 5303.7923224802. The cubic root of 28130213 is about 304.1288876662.

Adding to 28130213 its reverse (31203182), we get a palindrome (59333395).

The spelling of 28130213 in words is "twenty-eight million, one hundred thirty thousand, two hundred thirteen".