31555421211 has 4 divisors (see below), whose sum is σ = 42073894952. Its totient is φ = 21036947472.

The previous prime is 31555421201. The next prime is 31555421273. The reversal of 31555421211 is 11212455513.

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

It is not a de Polignac number, because 31555421211 - 2¹¹ = 31555419163 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31555421201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5259236866 + ... + 5259236871.

It is an arithmetic number, because the mean of its divisors is an integer number (10518473738).

Almost surely, 2^31555421211 is an apocalyptic number.

31555421211 is a deficient number, since it is larger than the sum of its proper divisors (10518473741).

31555421211 is a wasteful number, since it uses less digits than its factorization.

31555421211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10518473740.

The product of its digits is 6000, while the sum is 30.

Adding to 31555421211 its reverse (11212455513), we get a palindrome (42767876724).

The spelling of 31555421211 in words is "thirty-one billion, five hundred fifty-five million, four hundred twenty-one thousand, two hundred eleven".