311221031213 has 8 divisors (see below), whose sum is σ = 322103511480. Its totient is φ = 300348599040.

The previous prime is 311221031201. The next prime is 311221031221. The reversal of 311221031213 is 312130122113.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 38912644 + 311182118569 = 6238^2 + 557837^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 311221031213 - 2⁸ = 311221030957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (311221031113) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2448968 + ... + 2572913.

It is an arithmetic number, because the mean of its divisors is an integer number (40262938935).

Almost surely, 2^311221031213 is an apocalyptic number.

It is an amenable number.

311221031213 is a deficient number, since it is larger than the sum of its proper divisors (10882480267).

311221031213 is a wasteful number, since it uses less digits than its factorization.

311221031213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5024047.

The product of its (nonzero) digits is 216, while the sum is 20.

Adding to 311221031213 its reverse (312130122113), we get a palindrome (623351153326).

The spelling of 311221031213 in words is "three hundred eleven billion, two hundred twenty-one million, thirty-one thousand, two hundred thirteen".