1128556381 has 2 divisors, whose sum is σ = 1128556382. Its totient is φ = 1128556380.

The previous prime is 1128556379. The next prime is 1128556397. The reversal of 1128556381 is 1836558211.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 895505625 + 233050756 = 29925^2 + 15266^2 .

It is a cyclic number.

It is not a de Polignac number, because 1128556381 - 2¹ = 1128556379 is a prime.

It is a super-2 number, since 2×1128556381² = 2547279010191634322, which contains 22 as substring.

Together with 1128556379, 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 (1128556301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 564278190 + 564278191.

It is an arithmetic number, because the mean of its divisors is an integer number (564278191).

Almost surely, 2^1128556381 is an apocalyptic number.

It is an amenable number.

1128556381 is a deficient number, since it is larger than the sum of its proper divisors (1).

1128556381 is an equidigital number, since it uses as much as digits as its factorization.

1128556381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 57600, while the sum is 40.

The square root of 1128556381 is about 33593.9932279567. The cubic root of 1128556381 is about 1041.1366950983.

The spelling of 1128556381 in words is "one billion, one hundred twenty-eight million, five hundred fifty-six thousand, three hundred eighty-one".