311440312021 has 4 divisors (see below), whose sum is σ = 314297562700. Its totient is φ = 308583061344.

The previous prime is 311440311983. The next prime is 311440312037. The reversal of 311440312021 is 120213044113.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 120213044113 = 67 ⋅1794224539.

It can be written as a sum of positive squares in 2 ways, for example, as 105374248996 + 206066063025 = 324614^2 + 453945^2 .

It is a cyclic number.

It is not a de Polignac number, because 311440312021 - 2¹⁹ = 311439787733 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 311440311983 and 311440312001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (311440312081) 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, 1428625176 + ... + 1428625393.

It is an arithmetic number, because the mean of its divisors is an integer number (78574390675).

Almost surely, 2^311440312021 is an apocalyptic number.

It is an amenable number.

311440312021 is a deficient number, since it is larger than the sum of its proper divisors (2857250679).

311440312021 is a wasteful number, since it uses less digits than its factorization.

311440312021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2857250678.

The product of its (nonzero) digits is 576, while the sum is 22.

Adding to 311440312021 its reverse (120213044113), we get a palindrome (431653356134).

The spelling of 311440312021 in words is "three hundred eleven billion, four hundred forty million, three hundred twelve thousand, twenty-one".