31117312 has 52 divisors (see below), whose sum is σ = 63693216. Its totient is φ = 15196160.

The previous prime is 31117297. The next prime is 31117313. The reversal of 31117312 is 21371113.

It is a super-2 number, since 2×31117312² = 1936574212210688, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 31117312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31117313) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 290763 + ... + 290869.

Almost surely, 2^31117312 is an apocalyptic number.

31117312 is a gapful number since it is divisible by the number (32) 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 31117312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31846608).

31117312 is an abundant number, since it is smaller than the sum of its proper divisors (32575904).

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

31117312 is an equidigital number, since it uses as much as digits as its factorization.

31117312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202 (or 180 counting only the distinct ones).

The product of its digits is 126, while the sum is 19.

The square root of 31117312 is about 5578.2893435174. The cubic root of 31117312 is about 314.5338262731.

Adding to 31117312 its reverse (21371113), we get a palindrome (52488425).

The spelling of 31117312 in words is "thirty-one million, one hundred seventeen thousand, three hundred twelve".