31023221 has 4 divisors (see below), whose sum is σ = 31416000. Its totient is φ = 30630444.

The previous prime is 31023199. The next prime is 31023227. The reversal of 31023221 is 12232013.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 31023221 - 2¹⁰ = 31022197 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 31023196 and 31023205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31023227) 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, 196271 + ... + 196428.

It is an arithmetic number, because the mean of its divisors is an integer number (7854000).

Almost surely, 2^31023221 is an apocalyptic number.

It is an amenable number.

31023221 is a deficient number, since it is larger than the sum of its proper divisors (392779).

31023221 is an equidigital number, since it uses as much as digits as its factorization.

31023221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 392778.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 31023221 is about 5569.8492798280. The cubic root of 31023221 is about 314.2164822219.

Adding to 31023221 its reverse (12232013), we get a palindrome (43255234).

The spelling of 31023221 in words is "thirty-one million, twenty-three thousand, two hundred twenty-one".