13228021 has 2 divisors, whose sum is σ = 13228022. Its totient is φ = 13228020.

The previous prime is 13228003. The next prime is 13228037. The reversal of 13228021 is 12082231.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7535025 + 5692996 = 2745^2 + 2386^2 .

It is a cyclic number.

It is not a de Polignac number, because 13228021 - 2¹¹ = 13225973 is a prime.

It is equal to p₈₆₃₁₁₀ and since 13228021 and 863110 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 13228021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13228001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6614010 + 6614011.

It is an arithmetic number, because the mean of its divisors is an integer number (6614011).

Almost surely, 2^13228021 is an apocalyptic number.

It is an amenable number.

13228021 is a deficient number, since it is larger than the sum of its proper divisors (1).

13228021 is an equidigital number, since it uses as much as digits as its factorization.

13228021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 13228021 is about 3637.0346437723. The cubic root of 13228021 is about 236.5002614768.

The spelling of 13228021 in words is "thirteen million, two hundred twenty-eight thousand, twenty-one".