1261121668063 has 2 divisors, whose sum is σ = 1261121668064. Its totient is φ = 1261121668062.

The previous prime is 1261121668057. The next prime is 1261121668069. The reversal of 1261121668063 is 3608661211621.

It is a balanced prime because it is at equal distance from previous prime (1261121668057) and next prime (1261121668069).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1261121668063 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1261121668069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630560834031 + 630560834032.

It is an arithmetic number, because the mean of its divisors is an integer number (630560834032).

Almost surely, 2^{1261121668063} is an apocalyptic number.

1261121668063 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261121668063 is an equidigital number, since it uses as much as digits as its factorization.

1261121668063 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 124416, while the sum is 43.

Adding to 1261121668063 its reverse (3608661211621), we get a palindrome (4869782879684).

The spelling of 1261121668063 in words is "one trillion, two hundred sixty-one billion, one hundred twenty-one million, six hundred sixty-eight thousand, sixty-three".