28663213 has 2 divisors, whose sum is σ = 28663214. Its totient is φ = 28663212.

The previous prime is 28663199. The next prime is 28663237. The reversal of 28663213 is 31236682.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19342404 + 9320809 = 4398^2 + 3053^2 .

It is a cyclic number.

It is not a de Polignac number, because 28663213 - 2⁵ = 28663181 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28663253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14331606 + 14331607.

It is an arithmetic number, because the mean of its divisors is an integer number (14331607).

Almost surely, 2^28663213 is an apocalyptic number.

It is an amenable number.

28663213 is a deficient number, since it is larger than the sum of its proper divisors (1).

28663213 is an equidigital number, since it uses as much as digits as its factorization.

28663213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 31.

The square root of 28663213 is about 5353.8036011793. The cubic root of 28663213 is about 306.0377194450.

Adding to 28663213 its reverse (31236682), we get a palindrome (59899895).

The spelling of 28663213 in words is "twenty-eight million, six hundred sixty-three thousand, two hundred thirteen".