31313131333021 has 16 divisors (see below), whose sum is σ = 31494323367936. Its totient is φ = 31132462421376.

The previous prime is 31313131333007. The next prime is 31313131333049. The reversal of 31313131333021 is 12033313131313.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31313131333021 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 (31313131333621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 320542641 + ... + 320640313.

It is an arithmetic number, because the mean of its divisors is an integer number (1968395210496).

Almost surely, 2^{31313131333021} is an apocalyptic number.

It is an amenable number.

31313131333021 is a deficient number, since it is larger than the sum of its proper divisors (181192034915).

31313131333021 is a wasteful number, since it uses less digits than its factorization.

31313131333021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100332.

The product of its (nonzero) digits is 4374, while the sum is 28.

Adding to 31313131333021 its reverse (12033313131313), we get a palindrome (43346444464334).

The spelling of 31313131333021 in words is "thirty-one trillion, three hundred thirteen billion, one hundred thirty-one million, three hundred thirty-three thousand, twenty-one".