1228824721 has 2 divisors, whose sum is σ = 1228824722. Its totient is φ = 1228824720.

The previous prime is 1228824679. The next prime is 1228824757. The reversal of 1228824721 is 1274288221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1202702400 + 26122321 = 34680^2 + 5111^2 .

It is a cyclic number.

It is not a de Polignac number, because 1228824721 - 2¹³ = 1228816529 is a prime.

It is not a weakly prime, because it can be changed into another prime (1228824781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 614412360 + 614412361.

It is an arithmetic number, because the mean of its divisors is an integer number (614412361).

Almost surely, 2^1228824721 is an apocalyptic number.

It is an amenable number.

1228824721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1228824721 is an equidigital number, since it uses as much as digits as its factorization.

1228824721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 28672, while the sum is 37.

The square root of 1228824721 is about 35054.5962892172. The cubic root of 1228824721 is about 1071.0999028316.

The spelling of 1228824721 in words is "one billion, two hundred twenty-eight million, eight hundred twenty-four thousand, seven hundred twenty-one".