31021211213 has 24 divisors (see below), whose sum is σ = 32991707448. Its totient is φ = 29163483648.

The previous prime is 31021211203. The next prime is 31021211293. The reversal of 31021211213 is 31211212013.

It can be written as a sum of positive squares in 4 ways, for example, as 46267204 + 30974944009 = 6802^2 + 175997^2 .

It is not a de Polignac number, because 31021211213 - 2⁶ = 31021211149 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31021211191 and 31021211200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31021211203) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 33106481 + ... + 33107417.

It is an arithmetic number, because the mean of its divisors is an integer number (1374654477).

Almost surely, 2^31021211213 is an apocalyptic number.

It is an amenable number.

31021211213 is a deficient number, since it is larger than the sum of its proper divisors (1970496235).

31021211213 is a wasteful number, since it uses less digits than its factorization.

31021211213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1581 (or 1562 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 31021211213 its reverse (31211212013), we get a palindrome (62232423226).

The spelling of 31021211213 in words is "thirty-one billion, twenty-one million, two hundred eleven thousand, two hundred thirteen".