1311005023 has 4 divisors (see below), whose sum is σ = 1316631888. Its totient is φ = 1305378160.

The previous prime is 1311005011. The next prime is 1311005039. The reversal of 1311005023 is 3205001131.

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 1311005023 - 2²¹ = 1308907871 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1311004988 and 1311005006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311005093) 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, 2813083 + ... + 2813548.

It is an arithmetic number, because the mean of its divisors is an integer number (329157972).

Almost surely, 2^1311005023 is an apocalyptic number.

1311005023 is a deficient number, since it is larger than the sum of its proper divisors (5626865).

1311005023 is an equidigital number, since it uses as much as digits as its factorization.

1311005023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5626864.

The product of its (nonzero) digits is 90, while the sum is 16.

The square root of 1311005023 is about 36207.8033440307. The cubic root of 1311005023 is about 1094.4639266984.

Adding to 1311005023 its reverse (3205001131), we get a palindrome (4516006154).

The spelling of 1311005023 in words is "one billion, three hundred eleven million, five thousand, twenty-three".