312031232221 has 4 divisors (see below), whose sum is σ = 312032769372. Its totient is φ = 312029695072.

The previous prime is 312031232213. The next prime is 312031232267. The reversal of 312031232221 is 122232130213.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 268312604121 + 43718628100 = 517989^2 + 209090^2 .

It is a cyclic number.

It is not a de Polignac number, because 312031232221 - 2³ = 312031232213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 312031232192 and 312031232201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (312031232281) 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, 407560 + ... + 888913.

It is an arithmetic number, because the mean of its divisors is an integer number (78008192343).

Almost surely, 2^312031232221 is an apocalyptic number.

It is an amenable number.

312031232221 is a deficient number, since it is larger than the sum of its proper divisors (1537151).

312031232221 is a wasteful number, since it uses less digits than its factorization.

312031232221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1537150.

The product of its (nonzero) digits is 864, while the sum is 22.

Adding to 312031232221 its reverse (122232130213), we get a palindrome (434263362434).

The spelling of 312031232221 in words is "three hundred twelve billion, thirty-one million, two hundred thirty-two thousand, two hundred twenty-one".