31031020213 has 4 divisors (see below), whose sum is σ = 31045597740. Its totient is φ = 31016442688.

The previous prime is 31031020201. The next prime is 31031020217. The reversal of 31031020213 is 31202013013.

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 9081708804 + 21949311409 = 95298^2 + 148153^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31031020213 is a prime.

It is a super-2 number, since 2×31031020213² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31031020217) 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, 7285570 + ... + 7289827.

It is an arithmetic number, because the mean of its divisors is an integer number (7761399435).

Almost surely, 2^31031020213 is an apocalyptic number.

It is an amenable number.

31031020213 is a deficient number, since it is larger than the sum of its proper divisors (14577527).

31031020213 is a wasteful number, since it uses less digits than its factorization.

31031020213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14577526.

The product of its (nonzero) digits is 108, while the sum is 16.

Adding to 31031020213 its reverse (31202013013), we get a palindrome (62233033226).

The spelling of 31031020213 in words is "thirty-one billion, thirty-one million, twenty thousand, two hundred thirteen".