1113128561 has 2 divisors, whose sum is σ = 1113128562. Its totient is φ = 1113128560.

The previous prime is 1113128551. The next prime is 1113128579. The reversal of 1113128561 is 1658213111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1046134336 + 66994225 = 32344^2 + 8185^2 .

It is a cyclic number.

It is not a de Polignac number, because 1113128561 - 2¹⁰ = 1113127537 is a prime.

It is not a weakly prime, because it can be changed into another prime (1113128531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 556564280 + 556564281.

It is an arithmetic number, because the mean of its divisors is an integer number (556564281).

Almost surely, 2^1113128561 is an apocalyptic number.

It is an amenable number.

1113128561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1113128561 is an equidigital number, since it uses as much as digits as its factorization.

1113128561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1440, while the sum is 29.

The square root of 1113128561 is about 33363.5813575222. The cubic root of 1113128561 is about 1036.3706582181.

The spelling of 1113128561 in words is "one billion, one hundred thirteen million, one hundred twenty-eight thousand, five hundred sixty-one".