31110121220 has 12 divisors (see below), whose sum is σ = 65331254604. Its totient is φ = 12444048480.

The previous prime is 31110121199. The next prime is 31110121253. The reversal of 31110121220 is 2212101113.

It can be written as a sum of positive squares in 2 ways, for example, as 23825157316 + 7284963904 = 154354^2 + 85352^2 .

It is a junction number, because it is equal to n+sod(n) for n = 31110121195 and 31110121204.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 777753011 + ... + 777753050.

It is an arithmetic number, because the mean of its divisors is an integer number (5444271217).

Almost surely, 2^31110121220 is an apocalyptic number.

It is an amenable number.

31110121220 is an abundant number, since it is smaller than the sum of its proper divisors (34221133384).

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

31110121220 is a wasteful number, since it uses less digits than its factorization.

31110121220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1555506070 (or 1555506068 counting only the distinct ones).

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

Adding to 31110121220 its reverse (2212101113), we get a palindrome (33322222333).

The spelling of 31110121220 in words is "thirty-one billion, one hundred ten million, one hundred twenty-one thousand, two hundred twenty".