31120311220 has 48 divisors (see below), whose sum is σ = 67660745040. Its totient is φ = 12009181184.

The previous prime is 31120311203. The next prime is 31120311227. The reversal of 31120311220 is 2211302113.

It can be written as a sum of positive squares in 8 ways, for example, as 1084648356 + 30035662864 = 32934^2 + 173308^2 .

It is a super-3 number, since 3×31120311220³ (a number of 32 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31120311194 and 31120311203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31120311227) 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, 719652 + ... + 761668.

It is an arithmetic number, because the mean of its divisors is an integer number (1409598855).

Almost surely, 2^31120311220 is an apocalyptic number.

It is an amenable number.

31120311220 is an abundant number, since it is smaller than the sum of its proper divisors (36540433820).

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

31120311220 is a wasteful number, since it uses less digits than its factorization.

31120311220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43332 (or 43330 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 31120311220 its reverse (2211302113), we get a palindrome (33331613333).

The spelling of 31120311220 in words is "thirty-one billion, one hundred twenty million, three hundred eleven thousand, two hundred twenty".