31221113013 has 16 divisors (see below), whose sum is σ = 47037460800. Its totient is φ = 20461293360.

The previous prime is 31221113009. The next prime is 31221113023. The reversal of 31221113013 is 31031112213.

31221113013 is a `hidden beast` number, since 312 + 211 + 130 + 13 = 666.

It is not a de Polignac number, because 31221113013 - 2² = 31221113009 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31221113023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9797878 + ... + 9801063.

It is an arithmetic number, because the mean of its divisors is an integer number (2939841300).

Almost surely, 2^31221113013 is an apocalyptic number.

It is an amenable number.

31221113013 is a deficient number, since it is larger than the sum of its proper divisors (15816347787).

31221113013 is a wasteful number, since it uses less digits than its factorization.

31221113013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19599009 (or 19599003 counting only the distinct ones).

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

Adding to 31221113013 its reverse (31031112213), we get a palindrome (62252225226).

The spelling of 31221113013 in words is "thirty-one billion, two hundred twenty-one million, one hundred thirteen thousand, thirteen".