31213424 has 40 divisors (see below), whose sum is σ = 66983808. Its totient is φ = 13970880.

The previous prime is 31213417. The next prime is 31213433. The reversal of 31213424 is 42431213.

It is a junction number, because it is equal to n+sod(n) for n = 31213396 and 31213405.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10469 + ... + 13115.

Almost surely, 2^31213424 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31213424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33491904).

31213424 is an abundant number, since it is smaller than the sum of its proper divisors (35770384).

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

31213424 is a wasteful number, since it uses less digits than its factorization.

31213424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2733 (or 2727 counting only the distinct ones).

The product of its digits is 576, while the sum is 20.

The square root of 31213424 is about 5586.8975290406. The cubic root of 31213424 is about 314.8573268391.

Adding to 31213424 its reverse (42431213), we get a palindrome (73644637).

The spelling of 31213424 in words is "thirty-one million, two hundred thirteen thousand, four hundred twenty-four".