31320322221 has 16 divisors (see below), whose sum is σ = 42519052800. Its totient is φ = 20501750448.

The previous prime is 31320322213. The next prime is 31320322223. The reversal of 31320322221 is 12222302313.

It is a happy number.

It is not a de Polignac number, because 31320322221 - 2³ = 31320322213 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31320322223) 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, 43050 + ... + 253956.

It is an arithmetic number, because the mean of its divisors is an integer number (2657440800).

Almost surely, 2^31320322221 is an apocalyptic number.

It is an amenable number.

31320322221 is a deficient number, since it is larger than the sum of its proper divisors (11198730579).

31320322221 is a wasteful number, since it uses less digits than its factorization.

31320322221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211808.

The product of its (nonzero) digits is 864, while the sum is 21.

Adding to 31320322221 its reverse (12222302313), we get a palindrome (43542624534).

The spelling of 31320322221 in words is "thirty-one billion, three hundred twenty million, three hundred twenty-two thousand, two hundred twenty-one".