31320332221 has 4 divisors (see below), whose sum is σ = 31402972000. Its totient is φ = 31237692444.

The previous prime is 31320332213. The next prime is 31320332233. The reversal of 31320332221 is 12223302313.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 31320332221 - 2³ = 31320332213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31320332192 and 31320332201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31320332201) 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, 41319321 + ... + 41320078.

It is an arithmetic number, because the mean of its divisors is an integer number (7850743000).

Almost surely, 2^31320332221 is an apocalyptic number.

It is an amenable number.

31320332221 is a deficient number, since it is larger than the sum of its proper divisors (82639779).

31320332221 is an equidigital number, since it uses as much as digits as its factorization.

31320332221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82639778.

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

Adding to 31320332221 its reverse (12223302313), we get a palindrome (43543634534).

The spelling of 31320332221 in words is "thirty-one billion, three hundred twenty million, three hundred thirty-two thousand, two hundred twenty-one".