1311023021 has 32 divisors (see below), whose sum is σ = 1658044416. Its totient is φ = 1015383600.

The previous prime is 1311023003. The next prime is 1311023033. The reversal of 1311023021 is 1203201131.

It is not a de Polignac number, because 1311023021 - 2¹⁴ = 1311006637 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1311022987 and 1311023005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311023071) 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 31 ways as a sum of consecutive naturals, for example, 2077376 + ... + 2078006.

It is an arithmetic number, because the mean of its divisors is an integer number (51813888).

Almost surely, 2^1311023021 is an apocalyptic number.

1311023021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1311023021 is a deficient number, since it is larger than the sum of its proper divisors (347021395).

1311023021 is an equidigital number, since it uses as much as digits as its factorization.

1311023021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 894 (or 872 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 14.

The square root of 1311023021 is about 36208.0518807627. The cubic root of 1311023021 is about 1094.4689350879.

Adding to 1311023021 its reverse (1203201131), we get a palindrome (2514224152).

The spelling of 1311023021 in words is "one billion, three hundred eleven million, twenty-three thousand, twenty-one".