28660321 has 2 divisors, whose sum is σ = 28660322. Its totient is φ = 28660320.

The previous prime is 28660279. The next prime is 28660327. The reversal of 28660321 is 12306682.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27709696 + 950625 = 5264^2 + 975^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28660321 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28660321.

It is not a weakly prime, because it can be changed into another prime (28660327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14330160 + 14330161.

It is an arithmetic number, because the mean of its divisors is an integer number (14330161).

Almost surely, 2^28660321 is an apocalyptic number.

It is an amenable number.

28660321 is a deficient number, since it is larger than the sum of its proper divisors (1).

28660321 is an equidigital number, since it uses as much as digits as its factorization.

28660321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 28660321 is about 5353.5335060126. The cubic root of 28660321 is about 306.0274264508.

The spelling of 28660321 in words is "twenty-eight million, six hundred sixty thousand, three hundred twenty-one".