931212221221 has 8 divisors (see below), whose sum is σ = 971847973080. Its totient is φ = 891144801792.

The previous prime is 931212221207. The next prime is 931212221257. The reversal of 931212221221 is 122122212139.

It can be written as a sum of positive squares in 4 ways, for example, as 84602448225 + 846609772996 = 290865^2 + 920114^2 .

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

It is not a de Polignac number, because 931212221221 - 2¹⁵ = 931212188453 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 931212221221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (931212221281) 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 7 ways as a sum of consecutive naturals, for example, 142079760 + ... + 142086313.

It is an arithmetic number, because the mean of its divisors is an integer number (121480996635).

Almost surely, 2^931212221221 is an apocalyptic number.

It is an amenable number.

931212221221 is a deficient number, since it is larger than the sum of its proper divisors (40635751859).

931212221221 is a wasteful number, since it uses less digits than its factorization.

931212221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 284166215.

The product of its digits is 1728, while the sum is 28.

The spelling of 931212221221 in words is "nine hundred thirty-one billion, two hundred twelve million, two hundred twenty-one thousand, two hundred twenty-one".