31323220321 has 16 divisors (see below), whose sum is σ = 32135823360. Its totient is φ = 30519253440.

The previous prime is 31323220297. The next prime is 31323220343. The reversal of 31323220321 is 12302232313.

It is a cyclic number.

It is not a de Polignac number, because 31323220321 - 2¹¹ = 31323218273 is a prime.

It is a super-2 number, since 2×31323220321² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31323220292 and 31323220301.

It is not an unprimeable number, because it can be changed into a prime (31323220121) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11725816 + ... + 11728486.

It is an arithmetic number, because the mean of its divisors is an integer number (2008488960).

Almost surely, 2^31323220321 is an apocalyptic number.

It is an amenable number.

31323220321 is a deficient number, since it is larger than the sum of its proper divisors (812603039).

31323220321 is a wasteful number, since it uses less digits than its factorization.

31323220321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4176.

The product of its (nonzero) digits is 1296, while the sum is 22.

Adding to 31323220321 its reverse (12302232313), we get a palindrome (43625452634).

The spelling of 31323220321 in words is "thirty-one billion, three hundred twenty-three million, two hundred twenty thousand, three hundred twenty-one".