31020313221 has 6 divisors (see below), whose sum is σ = 44807119110. Its totient is φ = 20680208808.

The previous prime is 31020313211. The next prime is 31020313267. The reversal of 31020313221 is 12231302013.

31020313221 is a `hidden beast` number, since 310 + 2 + 0 + 31 + 322 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 30558536100 + 461777121 = 174810^2 + 21489^2 .

It is not a de Polignac number, because 31020313221 - 2²³ = 31011924613 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31020313194 and 31020313203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31020313201) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1723350726 + ... + 1723350743.

It is an arithmetic number, because the mean of its divisors is an integer number (7467853185).

Almost surely, 2^31020313221 is an apocalyptic number.

It is an amenable number.

31020313221 is a deficient number, since it is larger than the sum of its proper divisors (13786805889).

31020313221 is a wasteful number, since it uses less digits than its factorization.

31020313221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3446701475 (or 3446701472 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 31020313221 its reverse (12231302013), we get a palindrome (43251615234).

The spelling of 31020313221 in words is "thirty-one billion, twenty million, three hundred thirteen thousand, two hundred twenty-one".