31214221 has 4 divisors (see below), whose sum is σ = 31500700. Its totient is φ = 30927744.

The previous prime is 31214219. The next prime is 31214231. The reversal of 31214221 is 12241213.

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

It can be written as a sum of positive squares in 2 ways, for example, as 28238596 + 2975625 = 5314^2 + 1725^2 .

It is a cyclic number.

It is not a de Polignac number, because 31214221 - 2¹ = 31214219 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31214195 and 31214204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31214201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 143076 + ... + 143293.

It is an arithmetic number, because the mean of its divisors is an integer number (7875175).

Almost surely, 2^31214221 is an apocalyptic number.

It is an amenable number.

31214221 is a deficient number, since it is larger than the sum of its proper divisors (286479).

31214221 is a wasteful number, since it uses less digits than its factorization.

31214221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 286478.

The product of its digits is 96, while the sum is 16.

The square root of 31214221 is about 5586.9688561867. The cubic root of 31214221 is about 314.8600066600.

Adding to 31214221 its reverse (12241213), we get a palindrome (43455434).

The spelling of 31214221 in words is "thirty-one million, two hundred fourteen thousand, two hundred twenty-one".