1311211023 has 4 divisors (see below), whose sum is σ = 1748281368. Its totient is φ = 874140680.

The previous prime is 1311211019. The next prime is 1311211049. The reversal of 1311211023 is 3201121131.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1311211023 - 2² = 1311211019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1311210993 and 1311211011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311211523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 218535168 + ... + 218535173.

It is an arithmetic number, because the mean of its divisors is an integer number (437070342).

Almost surely, 2^1311211023 is an apocalyptic number.

1311211023 is a deficient number, since it is larger than the sum of its proper divisors (437070345).

1311211023 is an equidigital number, since it uses as much as digits as its factorization.

1311211023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 437070344.

The product of its (nonzero) digits is 36, while the sum is 15.

The square root of 1311211023 is about 36210.6479229522. The cubic root of 1311211023 is about 1094.5212485639.

Adding to 1311211023 its reverse (3201121131), we get a palindrome (4512332154).

The spelling of 1311211023 in words is "one billion, three hundred eleven million, two hundred eleven thousand, twenty-three".