331131311031221 has 4 divisors (see below), whose sum is σ = 331132298483532. Its totient is φ = 331130323578912.

The previous prime is 331131311031197. The next prime is 331131311031259. The reversal of 331131311031221 is 122130113131133.

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 316954286304100 + 14177024727121 = 17803210^2 + 3765239^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-331131311031221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (331131341031221) 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, 493222976 + ... + 493893881.

It is an arithmetic number, because the mean of its divisors is an integer number (82783074620883).

Almost surely, 2^{331131311031221} is an apocalyptic number.

It is an amenable number.

331131311031221 is a deficient number, since it is larger than the sum of its proper divisors (987452311).

331131311031221 is an equidigital number, since it uses as much as digits as its factorization.

331131311031221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 987452310.

The product of its (nonzero) digits is 972, while the sum is 26.

Adding to 331131311031221 its reverse (122130113131133), we get a palindrome (453261424162354).

The spelling of 331131311031221 in words is "three hundred thirty-one trillion, one hundred thirty-one billion, three hundred eleven million, thirty-one thousand, two hundred twenty-one".