311130221 has 4 divisors (see below), whose sum is σ = 311459712. Its totient is φ = 310800732.

The previous prime is 311130217. The next prime is 311130227. The reversal of 311130221 is 122031113.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 122031113 = 311 ⋅392383.

It is a cyclic number.

It is not a de Polignac number, because 311130221 - 2² = 311130217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 311130196 and 311130205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (311130227) 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, 163325 + ... + 165218.

It is an arithmetic number, because the mean of its divisors is an integer number (77864928).

Almost surely, 2^311130221 is an apocalyptic number.

It is an amenable number.

311130221 is a deficient number, since it is larger than the sum of its proper divisors (329491).

311130221 is an equidigital number, since it uses as much as digits as its factorization.

311130221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 329490.

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

The square root of 311130221 is about 17638.8837798768. The cubic root of 311130221 is about 677.6114446555.

Adding to 311130221 its reverse (122031113), we get a palindrome (433161334).

The spelling of 311130221 in words is "three hundred eleven million, one hundred thirty thousand, two hundred twenty-one".