1311005665 has 8 divisors (see below), whose sum is σ = 1599871680. Its totient is φ = 1031027952.

The previous prime is 1311005653. The next prime is 1311005713. The reversal of 1311005665 is 5665001131.

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 1311005665 - 2⁹ = 1311005153 is a prime.

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, 2221749 + ... + 2222338.

It is an arithmetic number, because the mean of its divisors is an integer number (199983960).

Almost surely, 2^1311005665 is an apocalyptic number.

It is an amenable number.

1311005665 is a deficient number, since it is larger than the sum of its proper divisors (288866015).

1311005665 is an equidigital number, since it uses as much as digits as its factorization.

1311005665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4444151.

The product of its (nonzero) digits is 2700, while the sum is 28.

The square root of 1311005665 is about 36207.8122095219. The cubic root of 1311005665 is about 1094.4641053516.

Adding to 1311005665 its reverse (5665001131), we get a palindrome (6976006796).

The spelling of 1311005665 in words is "one billion, three hundred eleven million, five thousand, six hundred sixty-five".