1261383020129 has 2 divisors, whose sum is σ = 1261383020130. Its totient is φ = 1261383020128.

The previous prime is 1261383020123. The next prime is 1261383020237. The reversal of 1261383020129 is 9210203831621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1107813085729 + 153569934400 = 1052527^2 + 391880^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1261383020129 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1261383020092 and 1261383020101.

It is not a weakly prime, because it can be changed into another prime (1261383020123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630691510064 + 630691510065.

It is an arithmetic number, because the mean of its divisors is an integer number (630691510065).

Almost surely, 2^{1261383020129} is an apocalyptic number.

It is an amenable number.

1261383020129 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261383020129 is an equidigital number, since it uses as much as digits as its factorization.

1261383020129 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 38.

The spelling of 1261383020129 in words is "one trillion, two hundred sixty-one billion, three hundred eighty-three million, twenty thousand, one hundred twenty-nine".