31530224 has 40 divisors (see below), whose sum is σ = 68805120. Its totient is φ = 13867200.

The previous prime is 31530211. The next prime is 31530269. The reversal of 31530224 is 42203513.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 31530196 and 31530205.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2567 + ... + 8345.

It is an arithmetic number, because the mean of its divisors is an integer number (1720128).

Almost surely, 2^31530224 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 31530224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34402560).

31530224 is an abundant number, since it is smaller than the sum of its proper divisors (37274896).

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

31530224 is a wasteful number, since it uses less digits than its factorization.

31530224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5829 (or 5823 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 20.

The square root of 31530224 is about 5615.1780025214. The cubic root of 31530224 is about 315.9189558762.

Adding to 31530224 its reverse (42203513), we get a palindrome (73733737).

Subtracting 31530224 from its reverse (42203513), we obtain a square (10673289 = 3267²).

The spelling of 31530224 in words is "thirty-one million, five hundred thirty thousand, two hundred twenty-four".