31313101221 has 48 divisors (see below), whose sum is σ = 48970496640. Its totient is φ = 19213407360.

The previous prime is 31313101207. The next prime is 31313101249. The reversal of 31313101221 is 12210131313.

31313101221 is a `hidden beast` number, since 3 + 131 + 310 + 1 + 221 = 666.

It is not a de Polignac number, because 31313101221 - 2²² = 31308906917 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31313101194 and 31313101203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31313101201) 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, 4697631 + ... + 4704291.

It is an arithmetic number, because the mean of its divisors is an integer number (1020218680).

Almost surely, 2^31313101221 is an apocalyptic number.

It is an amenable number.

31313101221 is a deficient number, since it is larger than the sum of its proper divisors (17657395419).

31313101221 is a wasteful number, since it uses less digits than its factorization.

31313101221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7466 (or 7463 counting only the distinct ones).

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

Adding to 31313101221 its reverse (12210131313), we get a palindrome (43523232534).

The spelling of 31313101221 in words is "thirty-one billion, three hundred thirteen million, one hundred one thousand, two hundred twenty-one".