28221169 has 2 divisors, whose sum is σ = 28221170. Its totient is φ = 28221168.

The previous prime is 28221133. The next prime is 28221181. The reversal of 28221169 is 96112282.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26010000 + 2211169 = 5100^2 + 1487^2 .

It is a cyclic number.

It is not a de Polignac number, because 28221169 - 2⁹ = 28220657 is a prime.

It is a super-2 number, since 2×28221169² = 1592868759453122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28221169.

It is not a weakly prime, because it can be changed into another prime (28221119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14110584 + 14110585.

It is an arithmetic number, because the mean of its divisors is an integer number (14110585).

Almost surely, 2^28221169 is an apocalyptic number.

It is an amenable number.

28221169 is a deficient number, since it is larger than the sum of its proper divisors (1).

28221169 is an equidigital number, since it uses as much as digits as its factorization.

28221169 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456, while the sum is 31.

The square root of 28221169 is about 5312.3600216853. The cubic root of 28221169 is about 304.4563242928.

The spelling of 28221169 in words is "twenty-eight million, two hundred twenty-one thousand, one hundred sixty-nine".