1231165550369 has 2 divisors, whose sum is σ = 1231165550370. Its totient is φ = 1231165550368.

The previous prime is 1231165550347. The next prime is 1231165550431. The reversal of 1231165550369 is 9630555611321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 799763547025 + 431402003344 = 894295^2 + 656812^2 .

It is a cyclic number.

It is not a de Polignac number, because 1231165550369 - 2⁸ = 1231165550113 is a prime.

It is a super-2 number, since 2×1231165550369² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1231165550339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615582775184 + 615582775185.

It is an arithmetic number, because the mean of its divisors is an integer number (615582775185).

Almost surely, 2^{1231165550369} is an apocalyptic number.

It is an amenable number.

1231165550369 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231165550369 is an equidigital number, since it uses as much as digits as its factorization.

1231165550369 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 729000, while the sum is 47.

The spelling of 1231165550369 in words is "one trillion, two hundred thirty-one billion, one hundred sixty-five million, five hundred fifty thousand, three hundred sixty-nine".