31212223 has 4 divisors (see below), whose sum is σ = 35671120. Its totient is φ = 26753328.

The previous prime is 31212197. The next prime is 31212227. The reversal of 31212223 is 32221213.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 31212223 - 2²¹ = 29115071 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31212197 and 31212206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31212227) 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, 2229438 + ... + 2229451.

It is an arithmetic number, because the mean of its divisors is an integer number (8917780).

Almost surely, 2^31212223 is an apocalyptic number.

31212223 is a deficient number, since it is larger than the sum of its proper divisors (4458897).

31212223 is an equidigital number, since it uses as much as digits as its factorization.

31212223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4458896.

The product of its digits is 144, while the sum is 16.

The square root of 31212223 is about 5586.7900443815. The cubic root of 31212223 is about 314.8532885285.

Adding to 31212223 its reverse (32221213), we get a palindrome (63433436).

The spelling of 31212223 in words is "thirty-one million, two hundred twelve thousand, two hundred twenty-three".