311231400221 has 24 divisors (see below), whose sum is σ = 374734926720. Its totient is φ = 257429189472.

The previous prime is 311231400217. The next prime is 311231400317. The reversal of 311231400221 is 122004132113.

It is not a de Polignac number, because 311231400221 - 2² = 311231400217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 311231400193 and 311231400202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (311231406221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2565296 + ... + 2683878.

It is an arithmetic number, because the mean of its divisors is an integer number (15613955280).

Almost surely, 2^311231400221 is an apocalyptic number.

It is an amenable number.

311231400221 is a deficient number, since it is larger than the sum of its proper divisors (63503526499).

311231400221 is a wasteful number, since it uses less digits than its factorization.

311231400221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120473 (or 120466 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 311231400221 its reverse (122004132113), we get a palindrome (433235532334).

The spelling of 311231400221 in words is "three hundred eleven billion, two hundred thirty-one million, four hundred thousand, two hundred twenty-one".