31223421 has 8 divisors (see below), whose sum is σ = 46256960. Its totient is φ = 20815596.

The previous prime is 31223419. The next prime is 31223429. The reversal of 31223421 is 12432213.

It is not a de Polignac number, because 31223421 - 2¹ = 31223419 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31223394 and 31223403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31223429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 578185 + ... + 578238.

It is an arithmetic number, because the mean of its divisors is an integer number (5782120).

Almost surely, 2^31223421 is an apocalyptic number.

It is an amenable number.

31223421 is a deficient number, since it is larger than the sum of its proper divisors (15033539).

31223421 is a wasteful number, since it uses less digits than its factorization.

31223421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1156432 (or 1156426 counting only the distinct ones).

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

The square root of 31223421 is about 5587.7921400138. The cubic root of 31223421 is about 314.8909373002.

Adding to 31223421 its reverse (12432213), we get a palindrome (43655634).

The spelling of 31223421 in words is "thirty-one million, two hundred twenty-three thousand, four hundred twenty-one".