31211323021013 has 4 divisors (see below), whose sum is σ = 31211344432428. Its totient is φ = 31211301609600.

The previous prime is 31211323021003. The next prime is 31211323021049. The reversal of 31211323021013 is 31012032311213.

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 28306422062884 + 2904900958129 = 5320378^2 + 1704377^2 .

It is a cyclic number.

It is not a de Polignac number, because 31211323021013 - 2²⁶ = 31211255912149 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31211323021013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31211323021003) 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, 8345756 + ... + 11492357.

It is an arithmetic number, because the mean of its divisors is an integer number (7802836108107).

Almost surely, 2^{31211323021013} is an apocalyptic number.

It is an amenable number.

31211323021013 is a deficient number, since it is larger than the sum of its proper divisors (21411415).

31211323021013 is a wasteful number, since it uses less digits than its factorization.

31211323021013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21411414.

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

Adding to 31211323021013 its reverse (31012032311213), we get a palindrome (62223355332226).

The spelling of 31211323021013 in words is "thirty-one trillion, two hundred eleven billion, three hundred twenty-three million, twenty-one thousand, thirteen".