31103211330221 has 4 divisors (see below), whose sum is σ = 31128852890652. Its totient is φ = 31077569769792.

The previous prime is 31103211330203. The next prime is 31103211330223. The reversal of 31103211330221 is 12203311230113.

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 2663538241225 + 28439673088996 = 1632035^2 + 5332886^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31103211330221 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 (31103211330223) 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, 12820778396 + ... + 12820780821.

It is an arithmetic number, because the mean of its divisors is an integer number (7782213222663).

Almost surely, 2^{31103211330221} is an apocalyptic number.

It is an amenable number.

31103211330221 is a deficient number, since it is larger than the sum of its proper divisors (25641560431).

31103211330221 is a wasteful number, since it uses less digits than its factorization.

31103211330221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25641560430.

The product of its (nonzero) digits is 648, while the sum is 23.

Adding to 31103211330221 its reverse (12203311230113), we get a palindrome (43306522560334).

The spelling of 31103211330221 in words is "thirty-one trillion, one hundred three billion, two hundred eleven million, three hundred thirty thousand, two hundred twenty-one".