31120321221 has 24 divisors (see below), whose sum is σ = 49043651904. Its totient is φ = 18858658560.

The previous prime is 31120321201. The next prime is 31120321247. The reversal of 31120321221 is 12212302113.

31120321221 is a `hidden beast` number, since 3 + 1 + 120 + 321 + 221 = 666.

It is not a de Polignac number, because 31120321221 - 2¹⁷ = 31120190149 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31120321194 and 31120321203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31120321201) 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, 1550965 + ... + 1570901.

It is an arithmetic number, because the mean of its divisors is an integer number (2043485496).

Almost surely, 2^31120321221 is an apocalyptic number.

It is an amenable number.

31120321221 is a deficient number, since it is larger than the sum of its proper divisors (17923330683).

31120321221 is a wasteful number, since it uses less digits than its factorization.

31120321221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35721 (or 35718 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 31120321221 its reverse (12212302113), we get a palindrome (43332623334).

The spelling of 31120321221 in words is "thirty-one billion, one hundred twenty million, three hundred twenty-one thousand, two hundred twenty-one".