31144221 has 48 divisors (see below), whose sum is σ = 50139648. Its totient is φ = 18547200.

The previous prime is 31144207. The next prime is 31144241. The reversal of 31144221 is 12244113.

It is not a de Polignac number, because 31144221 - 2¹⁰ = 31143197 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31144194 and 31144203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31144241) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 438616 + ... + 438686.

It is an arithmetic number, because the mean of its divisors is an integer number (1044576).

Almost surely, 2^31144221 is an apocalyptic number.

It is an amenable number.

31144221 is a deficient number, since it is larger than the sum of its proper divisors (18995427).

31144221 is a wasteful number, since it uses less digits than its factorization.

31144221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202 (or 199 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 31144221 is about 5580.7007624491. The cubic root of 31144221 is about 314.6244655523.

Adding to 31144221 its reverse (12244113), we get a palindrome (43388334).

The spelling of 31144221 in words is "thirty-one million, one hundred forty-four thousand, two hundred twenty-one".