31121220300000 has 288 divisors, whose sum is σ = 102130150002048. Its totient is φ = 8297352000000.

The previous prime is 31121220299933. The next prime is 31121220300007. The reversal of 31121220300000 is 302212113.

It is a super-2 number, since 2×31121220300000² (a number of 28 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31121220300007) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2727294295 + ... + 2727305705.

It is an arithmetic number, because the mean of its divisors is an integer number (354618576396).

Almost surely, 2^{31121220300000} is an apocalyptic number.

31121220300000 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31121220300000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51065075001024).

31121220300000 is an abundant number, since it is smaller than the sum of its proper divisors (71008929702048).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31121220300000 is an equidigital number, since it uses as much as digits as its factorization.

31121220300000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20540 (or 20512 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 31121220300000 its reverse (302212113), we get a palindrome (31121522512113).

The spelling of 31121220300000 in words is "thirty-one trillion, one hundred twenty-one billion, two hundred twenty million, three hundred thousand".