1311061250605 has 8 divisors (see below), whose sum is σ = 1574187673464. Its totient is φ = 1048239552000.

The previous prime is 1311061250581. The next prime is 1311061250651. The reversal of 1311061250605 is 5060521601131.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 536882994729 + 774178255876 = 732723^2 + 879874^2 .

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

It is a de Polignac number, because none of the positive numbers 2^k-1311061250605 is a prime.

It is a super-2 number, since 2×1311061250605² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 76171596 + ... + 76188805.

It is an arithmetic number, because the mean of its divisors is an integer number (196773459183).

Almost surely, 2^{1311061250605} is an apocalyptic number.

It is an amenable number.

1311061250605 is a deficient number, since it is larger than the sum of its proper divisors (263126422859).

1311061250605 is a wasteful number, since it uses less digits than its factorization.

1311061250605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152362127.

The product of its (nonzero) digits is 5400, while the sum is 31.

Adding to 1311061250605 its reverse (5060521601131), we get a palindrome (6371582851736).

The spelling of 1311061250605 in words is "one trillion, three hundred eleven billion, sixty-one million, two hundred fifty thousand, six hundred five".