28241921 has 2 divisors, whose sum is σ = 28241922. Its totient is φ = 28241920.

The previous prime is 28241909. The next prime is 28241933. The reversal of 28241921 is 12914282.

It is a balanced prime because it is at equal distance from previous prime (28241909) and next prime (28241933).

It can be written as a sum of positive squares in only one way, i.e., 26666896 + 1575025 = 5164^2 + 1255^2 .

It is a cyclic number.

It is not a de Polignac number, because 28241921 - 2¹⁴ = 28225537 is a prime.

It is a super-2 number, since 2×28241921² = 1595212203540482, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (28241021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14120960 + 14120961.

It is an arithmetic number, because the mean of its divisors is an integer number (14120961).

Almost surely, 2^28241921 is an apocalyptic number.

It is an amenable number.

28241921 is a deficient number, since it is larger than the sum of its proper divisors (1).

28241921 is an equidigital number, since it uses as much as digits as its factorization.

28241921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2304, while the sum is 29.

The square root of 28241921 is about 5314.3128436327. The cubic root of 28241921 is about 304.5309317578.

The spelling of 28241921 in words is "twenty-eight million, two hundred forty-one thousand, nine hundred twenty-one".