3131311221 has 48 divisors (see below), whose sum is σ = 4908384000. Its totient is φ = 1919078784.

The previous prime is 3131311219. The next prime is 3131311303. The reversal of 3131311221 is 1221131313.

3131311221 is a `hidden beast` number, since 3 + 131 + 311 + 221 = 666.

It is not a de Polignac number, because 3131311221 - 2¹ = 3131311219 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 3131311194 and 3131311203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3131311201) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 450430 + ... + 457328.

It is an arithmetic number, because the mean of its divisors is an integer number (102258000).

Almost surely, 2^3131311221 is an apocalyptic number.

It is an amenable number.

3131311221 is a deficient number, since it is larger than the sum of its proper divisors (1777072779).

3131311221 is a wasteful number, since it uses less digits than its factorization.

3131311221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7018 (or 7015 counting only the distinct ones).

The product of its digits is 108, while the sum is 18.

The square root of 3131311221 is about 55958.1202418380. The cubic root of 3131311221 is about 1462.9924271233.

Adding to 3131311221 its reverse (1221131313), we get a palindrome (4352442534).

The spelling of 3131311221 in words is "three billion, one hundred thirty-one million, three hundred eleven thousand, two hundred twenty-one".