31223020 has 12 divisors (see below), whose sum is σ = 65568384. Its totient is φ = 12489200.

The previous prime is 31222991. The next prime is 31223021. The reversal of 31223020 is 2032213.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (31223021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 780556 + ... + 780595.

It is an arithmetic number, because the mean of its divisors is an integer number (5464032).

Almost surely, 2^31223020 is an apocalyptic number.

It is an amenable number.

31223020 is an abundant number, since it is smaller than the sum of its proper divisors (34345364).

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

31223020 is a wasteful number, since it uses less digits than its factorization.

31223020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1561160 (or 1561158 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 13.

The square root of 31223020 is about 5587.7562581058. The cubic root of 31223020 is about 314.8895892544.

Adding to 31223020 its reverse (2032213), we get a palindrome (33255233).

It can be divided in two parts, 312 and 23020, that added together give a palindrome (23332).

The spelling of 31223020 in words is "thirty-one million, two hundred twenty-three thousand, twenty".