28581313 has 2 divisors, whose sum is σ = 28581314. Its totient is φ = 28581312.

The previous prime is 28581281. The next prime is 28581317. The reversal of 28581313 is 31318582.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27217089 + 1364224 = 5217^2 + 1168^2 .

It is a cyclic number.

It is not a de Polignac number, because 28581313 - 2⁵ = 28581281 is a prime.

It is not a weakly prime, because it can be changed into another prime (28581317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14290656 + 14290657.

It is an arithmetic number, because the mean of its divisors is an integer number (14290657).

Almost surely, 2^28581313 is an apocalyptic number.

It is an amenable number.

28581313 is a deficient number, since it is larger than the sum of its proper divisors (1).

28581313 is an equidigital number, since it uses as much as digits as its factorization.

28581313 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5760, while the sum is 31.

The square root of 28581313 is about 5346.1493619240. The cubic root of 28581313 is about 305.7459587176.

Adding to 28581313 its reverse (31318582), we get a palindrome (59899895).

The spelling of 28581313 in words is "twenty-eight million, five hundred eighty-one thousand, three hundred thirteen".