31231030221 has 16 divisors (see below), whose sum is σ = 46726297920. Its totient is φ = 20614539600.

The previous prime is 31231030169. The next prime is 31231030231. The reversal of 31231030221 is 12203013213.

31231030221 is a `hidden beast` number, since 31 + 2 + 310 + 302 + 21 = 666.

It is not a de Polignac number, because 31231030221 - 2¹⁵ = 31230997453 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 31231030194 and 31231030203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31231030231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5723535 + ... + 5728988.

It is an arithmetic number, because the mean of its divisors is an integer number (2920393620).

Almost surely, 2^31231030221 is an apocalyptic number.

It is an amenable number.

31231030221 is a deficient number, since it is larger than the sum of its proper divisors (15495267699).

31231030221 is a wasteful number, since it uses less digits than its factorization.

31231030221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11452633 (or 11452627 counting only the distinct ones).

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

Adding to 31231030221 its reverse (12203013213), we get a palindrome (43434043434).

The spelling of 31231030221 in words is "thirty-one billion, two hundred thirty-one million, thirty thousand, two hundred twenty-one".