31231033331221 has 8 divisors (see below), whose sum is σ = 31271827523840. Its totient is φ = 31190249458368.

The previous prime is 31231033331209. The next prime is 31231033331227. The reversal of 31231033331221 is 12213333013213.

It is a happy number.

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 31231033331221 - 2³³ = 31222443396629 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 31231033331221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31231033331227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3485980 + ... + 8637946.

It is an arithmetic number, because the mean of its divisors is an integer number (3908978440480).

Almost surely, 2^{31231033331221} is an apocalyptic number.

It is an amenable number.

31231033331221 is a deficient number, since it is larger than the sum of its proper divisors (40794192619).

31231033331221 is an equidigital number, since it uses as much as digits as its factorization.

31231033331221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5159883.

The product of its (nonzero) digits is 5832, while the sum is 28.

Adding to 31231033331221 its reverse (12213333013213), we get a palindrome (43444366344434).

The spelling of 31231033331221 in words is "thirty-one trillion, two hundred thirty-one billion, thirty-three million, three hundred thirty-one thousand, two hundred twenty-one".