31303113221 has 4 divisors (see below), whose sum is σ = 31354684032. Its totient is φ = 31251542412.

The previous prime is 31303113203. The next prime is 31303113241. The reversal of 31303113221 is 12231130313.

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 a de Polignac number, because none of the positive numbers 2^k-31303113221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 31303113193 and 31303113202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31303113241) 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, 25784495 + ... + 25785708.

It is an arithmetic number, because the mean of its divisors is an integer number (7838671008).

Almost surely, 2^31303113221 is an apocalyptic number.

It is an amenable number.

31303113221 is a deficient number, since it is larger than the sum of its proper divisors (51570811).

31303113221 is an equidigital number, since it uses as much as digits as its factorization.

31303113221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51570810.

The product of its (nonzero) digits is 324, while the sum is 20.

Adding to 31303113221 its reverse (12231130313), we get a palindrome (43534243534).

The spelling of 31303113221 in words is "thirty-one billion, three hundred three million, one hundred thirteen thousand, two hundred twenty-one".