31117220 has 12 divisors (see below), whose sum is σ = 65346204. Its totient is φ = 12446880.

The previous prime is 31117217. The next prime is 31117253. The reversal of 31117220 is 2271113.

It can be written as a sum of positive squares in 2 ways, for example, as 10903204 + 20214016 = 3302^2 + 4496^2 .

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, 777911 + ... + 777950.

It is an arithmetic number, because the mean of its divisors is an integer number (5445517).

Almost surely, 2^31117220 is an apocalyptic number.

It is an amenable number.

31117220 is an abundant number, since it is smaller than the sum of its proper divisors (34228984).

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

31117220 is a wasteful number, since it uses less digits than its factorization.

31117220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1555870 (or 1555868 counting only the distinct ones).

The product of its (nonzero) digits is 84, while the sum is 17.

The square root of 31117220 is about 5578.2810972557. The cubic root of 31117220 is about 314.5335162941.

Adding to 31117220 its reverse (2271113), we get a palindrome (33388333).

The spelling of 31117220 in words is "thirty-one million, one hundred seventeen thousand, two hundred twenty".