31103355221 has 4 divisors (see below), whose sum is σ = 31141802700. Its totient is φ = 31064907744.

The previous prime is 31103355187. The next prime is 31103355253. The reversal of 31103355221 is 12255330113.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 29635622500 + 1467732721 = 172150^2 + 38311^2 .

It is a cyclic number.

It is not a de Polignac number, because 31103355221 - 2¹⁴ = 31103338837 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31103355721) 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, 19222526 + ... + 19224143.

It is an arithmetic number, because the mean of its divisors is an integer number (7785450675).

Almost surely, 2^31103355221 is an apocalyptic number.

It is an amenable number.

31103355221 is a deficient number, since it is larger than the sum of its proper divisors (38447479).

31103355221 is an equidigital number, since it uses as much as digits as its factorization.

31103355221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38447478.

The product of its (nonzero) digits is 2700, while the sum is 26.

Adding to 31103355221 its reverse (12255330113), we get a palindrome (43358685334).

The spelling of 31103355221 in words is "thirty-one billion, one hundred three million, three hundred fifty-five thousand, two hundred twenty-one".