1261500115991 has 2 divisors, whose sum is σ = 1261500115992. Its totient is φ = 1261500115990.

The previous prime is 1261500115969. The next prime is 1261500116003. The reversal of 1261500115991 is 1995110051621.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1261500115991 - 2⁶ = 1261500115927 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1261500115901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630750057995 + 630750057996.

It is an arithmetic number, because the mean of its divisors is an integer number (630750057996).

Almost surely, 2^{1261500115991} is an apocalyptic number.

1261500115991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261500115991 is an equidigital number, since it uses as much as digits as its factorization.

1261500115991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24300, while the sum is 41.

The spelling of 1261500115991 in words is "one trillion, two hundred sixty-one billion, five hundred million, one hundred fifteen thousand, nine hundred ninety-one".