30531821121221 has 8 divisors (see below), whose sum is σ = 35605622299200. Its totient is φ = 26170132389324.

The previous prime is 30531821121181. The next prime is 30531821121247. The reversal of 30531821121221 is 12212112813503.

It is a de Polignac number, because none of the positive numbers 2^k-30531821121221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30531821121271) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44507027531 + ... + 44507028216.

It is an arithmetic number, because the mean of its divisors is an integer number (4450702787400).

Almost surely, 2^{30531821121221} is an apocalyptic number.

It is an amenable number.

30531821121221 is a deficient number, since it is larger than the sum of its proper divisors (5073801177979).

30531821121221 is an frugal number, since it uses more digits than its factorization.

30531821121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89014055768 (or 89014055754 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 32.

Adding to 30531821121221 its reverse (12212112813503), we get a palindrome (42743933934724).

The spelling of 30531821121221 in words is "thirty trillion, five hundred thirty-one billion, eight hundred twenty-one million, one hundred twenty-one thousand, two hundred twenty-one".