31243331221 has 8 divisors (see below), whose sum is σ = 34221904920. Its totient is φ = 28391505408.

The previous prime is 31243331083. The next prime is 31243331293. The reversal of 31243331221 is 12213334213.

It can be written as a sum of positive squares in 4 ways, for example, as 6008420196 + 25234911025 = 77514^2 + 158855^2 .

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 31243331221 - 2¹⁵ = 31243298453 is a prime.

It is a super-3 number, since 3×31243331221³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31243332221) 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, 31686456 + ... + 31687441.

It is an arithmetic number, because the mean of its divisors is an integer number (4277738115).

Almost surely, 2^31243331221 is an apocalyptic number.

It is an amenable number.

31243331221 is a deficient number, since it is larger than the sum of its proper divisors (2978573699).

31243331221 is a wasteful number, since it uses less digits than its factorization.

31243331221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63373943.

The product of its digits is 2592, while the sum is 25.

Adding to 31243331221 its reverse (12213334213), we get a palindrome (43456665434).

The spelling of 31243331221 in words is "thirty-one billion, two hundred forty-three million, three hundred thirty-one thousand, two hundred twenty-one".