1311021311 has 4 divisors (see below), whose sum is σ = 1311132192. Its totient is φ = 1310910432.

The previous prime is 1311021293. The next prime is 1311021323. The reversal of 1311021311 is 1131201131.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1311021311 - 2⁶ = 1311021247 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311021331) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 35255 + ... + 62168.

It is an arithmetic number, because the mean of its divisors is an integer number (327783048).

Almost surely, 2^1311021311 is an apocalyptic number.

1311021311 is a deficient number, since it is larger than the sum of its proper divisors (110881).

1311021311 is an equidigital number, since it uses as much as digits as its factorization.

1311021311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110880.

The product of its (nonzero) digits is 18, while the sum is 14.

The square root of 1311021311 is about 36208.0282672227. The cubic root of 1311021311 is about 1094.4684592400.

Adding to 1311021311 its reverse (1131201131), we get a palindrome (2442222442).

The spelling of 1311021311 in words is "one billion, three hundred eleven million, twenty-one thousand, three hundred eleven".