231221224 has 16 divisors (see below), whose sum is σ = 466889220. Its totient is φ = 106717440.

The previous prime is 231221209. The next prime is 231221239. The reversal of 231221224 is 422122132.

231221224 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (231221209) and next prime (231221239).

It can be written as a sum of positive squares in 2 ways, for example, as 228916900 + 2304324 = 15130^2 + 1518^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1111537 + ... + 1111744.

Almost surely, 2^231221224 is an apocalyptic number.

It is an amenable number.

231221224 is an abundant number, since it is smaller than the sum of its proper divisors (235667996).

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

231221224 is a wasteful number, since it uses less digits than its factorization.

231221224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2223300 (or 2223296 counting only the distinct ones).

The product of its digits is 384, while the sum is 19.

The square root of 231221224 is about 15205.9601472580. The cubic root of 231221224 is about 613.7750522582.

Adding to 231221224 its reverse (422122132), we get a palindrome (653343356).

The spelling of 231221224 in words is "two hundred thirty-one million, two hundred twenty-one thousand, two hundred twenty-four".