1128881389 has 2 divisors, whose sum is σ = 1128881390. Its totient is φ = 1128881388.

The previous prime is 1128881387. The next prime is 1128881401. The reversal of 1128881389 is 9831888211.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1109889225 + 18992164 = 33315^2 + 4358^2 .

It is a cyclic number.

It is not a de Polignac number, because 1128881389 - 2¹ = 1128881387 is a prime.

Together with 1128881387, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1128881387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 564440694 + 564440695.

It is an arithmetic number, because the mean of its divisors is an integer number (564440695).

Almost surely, 2^1128881389 is an apocalyptic number.

It is an amenable number.

1128881389 is a deficient number, since it is larger than the sum of its proper divisors (1).

1128881389 is an equidigital number, since it uses as much as digits as its factorization.

1128881389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 221184, while the sum is 49.

The square root of 1128881389 is about 33598.8301730879. The cubic root of 1128881389 is about 1041.2366296351.

The spelling of 1128881389 in words is "one billion, one hundred twenty-eight million, eight hundred eighty-one thousand, three hundred eighty-nine".