31121101220 has 48 divisors (see below), whose sum is σ = 72953673408. Its totient is φ = 11053580160.

The previous prime is 31121101189. The next prime is 31121101223. The reversal of 31121101220 is 2210112113.

It is a super-2 number, since 2×31121101220² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31121101195 and 31121101204.

It is not an unprimeable number, because it can be changed into a prime (31121101223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1635419 + ... + 1654338.

It is an arithmetic number, because the mean of its divisors is an integer number (1519868196).

Almost surely, 2^31121101220 is an apocalyptic number.

It is an amenable number.

31121101220 is an abundant number, since it is smaller than the sum of its proper divisors (41832572188).

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

31121101220 is a wasteful number, since it uses less digits than its factorization.

31121101220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3289820 (or 3289818 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 31121101220 its reverse (2210112113), we get a palindrome (33331213333).

The spelling of 31121101220 in words is "thirty-one billion, one hundred twenty-one million, one hundred one thousand, two hundred twenty".