1311375785 has 4 divisors (see below), whose sum is σ = 1573650948. Its totient is φ = 1049100624.

The previous prime is 1311375721. The next prime is 1311375803. The reversal of 1311375785 is 5875731131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5875731131 = 17 ⋅345631243.

It can be written as a sum of positive squares in 2 ways, for example, as 186377104 + 1124998681 = 13652^2 + 33541^2 .

It is a cyclic number.

It is not a de Polignac number, because 1311375785 - 2⁶ = 1311375721 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 131137574 + ... + 131137583.

It is an arithmetic number, because the mean of its divisors is an integer number (393412737).

Almost surely, 2^1311375785 is an apocalyptic number.

It is an amenable number.

1311375785 is a deficient number, since it is larger than the sum of its proper divisors (262275163).

1311375785 is an equidigital number, since it uses as much as digits as its factorization.

1311375785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262275162.

The product of its digits is 88200, while the sum is 41.

The square root of 1311375785 is about 36212.9229005337. The cubic root of 1311375785 is about 1094.5670911613.

The spelling of 1311375785 in words is "one billion, three hundred eleven million, three hundred seventy-five thousand, seven hundred eighty-five".