1131256129 has 2 divisors, whose sum is σ = 1131256130. Its totient is φ = 1131256128.

The previous prime is 1131256111. The next prime is 1131256151. The reversal of 1131256129 is 9216521311.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 832899600 + 298356529 = 28860^2 + 17273^2 .

It is a cyclic number.

It is not a de Polignac number, because 1131256129 - 2⁹ = 1131255617 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1131256129.

It is not a weakly prime, because it can be changed into another prime (1131256199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 565628064 + 565628065.

It is an arithmetic number, because the mean of its divisors is an integer number (565628065).

Almost surely, 2^1131256129 is an apocalyptic number.

It is an amenable number.

1131256129 is a deficient number, since it is larger than the sum of its proper divisors (1).

1131256129 is an equidigital number, since it uses as much as digits as its factorization.

1131256129 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3240, while the sum is 31.

The square root of 1131256129 is about 33634.1512305573. The cubic root of 1131256129 is about 1041.9662411099.

The spelling of 1131256129 in words is "one billion, one hundred thirty-one million, two hundred fifty-six thousand, one hundred twenty-nine".