28780213 has 16 divisors (see below), whose sum is σ = 36190080. Its totient is φ = 22418880.

The previous prime is 28780207. The next prime is 28780223. The reversal of 28780213 is 31208782.

It is not a de Polignac number, because 28780213 - 2⁵ = 28780181 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 (28780223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7773 + ... + 10861.

It is an arithmetic number, because the mean of its divisors is an integer number (2261880).

Almost surely, 2^28780213 is an apocalyptic number.

It is an amenable number.

28780213 is a deficient number, since it is larger than the sum of its proper divisors (7409867).

28780213 is an equidigital number, since it uses as much as digits as its factorization.

28780213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3129 (or 3107 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 28780213 is about 5364.7192843615. The cubic root of 28780213 is about 306.4535579638.

Adding to 28780213 its reverse (31208782), we get a palindrome (59988995).

The spelling of 28780213 in words is "twenty-eight million, seven hundred eighty thousand, two hundred thirteen".