1128198257 has 2 divisors, whose sum is σ = 1128198258. Its totient is φ = 1128198256.

The previous prime is 1128198229. The next prime is 1128198299. The reversal of 1128198257 is 7528918211.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 619064161 + 509134096 = 24881^2 + 22564^2 .

It is an emirp because it is prime and its reverse (7528918211) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1128198257 - 2¹⁶ = 1128132721 is a prime.

It is not a weakly prime, because it can be changed into another prime (1128198457) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 564099128 + 564099129.

It is an arithmetic number, because the mean of its divisors is an integer number (564099129).

Almost surely, 2^1128198257 is an apocalyptic number.

It is an amenable number.

1128198257 is a deficient number, since it is larger than the sum of its proper divisors (1).

1128198257 is an equidigital number, since it uses as much as digits as its factorization.

1128198257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 80640, while the sum is 44.

The square root of 1128198257 is about 33588.6626259516. The cubic root of 1128198257 is about 1041.0265557231.

The spelling of 1128198257 in words is "one billion, one hundred twenty-eight million, one hundred ninety-eight thousand, two hundred fifty-seven".