31224321 has 12 divisors (see below), whose sum is σ = 46151248. Its totient is φ = 20331864.

The previous prime is 31224313. The next prime is 31224341. The reversal of 31224321 is 12342213.

It is not a de Polignac number, because 31224321 - 2³ = 31224313 is a prime.

It is a super-2 number, since 2×31224321² = 1949916443822082, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31224294 and 31224303.

It is not an unprimeable number, because it can be changed into a prime (31224301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 39955 + ... + 40728.

Almost surely, 2^31224321 is an apocalyptic number.

It is an amenable number.

31224321 is a deficient number, since it is larger than the sum of its proper divisors (14926927).

31224321 is a wasteful number, since it uses less digits than its factorization.

31224321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80732 (or 80729 counting only the distinct ones).

The product of its digits is 288, while the sum is 18.

The square root of 31224321 is about 5587.8726721356. The cubic root of 31224321 is about 314.8939627974.

Adding to 31224321 its reverse (12342213), we get a palindrome (43566534).

The spelling of 31224321 in words is "thirty-one million, two hundred twenty-four thousand, three hundred twenty-one".