31224144 has 160 divisors (see below), whose sum is σ = 99834880. Its totient is φ = 8211456.

The previous prime is 31224113. The next prime is 31224199. The reversal of 31224144 is 44142213.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 31224144.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 427692 + ... + 427764.

It is an arithmetic number, because the mean of its divisors is an integer number (623968).

Almost surely, 2^31224144 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 31224144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49917440).

31224144 is an abundant number, since it is smaller than the sum of its proper divisors (68610736).

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

31224144 is a wasteful number, since it uses less digits than its factorization.

31224144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177 (or 171 counting only the distinct ones).

The product of its digits is 768, while the sum is 21.

The square root of 31224144 is about 5587.8568342433. The cubic root of 31224144 is about 314.8933677875.

Adding to 31224144 its reverse (44142213), we get a palindrome (75366357).

The spelling of 31224144 in words is "thirty-one million, two hundred twenty-four thousand, one hundred forty-four".