1311423406565 has 8 divisors (see below), whose sum is σ = 1573727515800. Its totient is φ = 1049125773312.

The previous prime is 1311423406529. The next prime is 1311423406589. The reversal of 1311423406565 is 5656043241131.

It can be written as a sum of positive squares in 4 ways, for example, as 145647563044 + 1165775843521 = 381638^2 + 1079711^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1311423406565 - 2¹⁰ = 1311423405541 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1161740 + ... + 1993109.

It is an arithmetic number, because the mean of its divisors is an integer number (196715939475).

Almost surely, 2^{1311423406565} is an apocalyptic number.

It is an amenable number.

1311423406565 is a deficient number, since it is larger than the sum of its proper divisors (262304109235).

1311423406565 is an equidigital number, since it uses as much as digits as its factorization.

1311423406565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3237991.

The product of its (nonzero) digits is 259200, while the sum is 41.

Adding to 1311423406565 its reverse (5656043241131), we get a palindrome (6967466647696).

The spelling of 1311423406565 in words is "one trillion, three hundred eleven billion, four hundred twenty-three million, four hundred six thousand, five hundred sixty-five".