31223420 has 48 divisors (see below), whose sum is σ = 69189120. Its totient is φ = 11812416.

The previous prime is 31223419. The next prime is 31223429. The reversal of 31223420 is 2432213.

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 polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47051 + ... + 47709.

It is an arithmetic number, because the mean of its divisors is an integer number (1441440).

Almost surely, 2^31223420 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 31223420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34594560).

31223420 is an abundant number, since it is smaller than the sum of its proper divisors (37965700).

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

31223420 is a wasteful number, since it uses less digits than its factorization.

31223420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 794 (or 792 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 17.

The square root of 31223420 is about 5587.7920505330. The cubic root of 31223420 is about 314.8909339385.

Adding to 31223420 its reverse (2432213), we get a palindrome (33655633).

It can be divided in two parts, 312 and 23420, that added together give a palindrome (23732).

The spelling of 31223420 in words is "thirty-one million, two hundred twenty-three thousand, four hundred twenty".