1224431221 has 4 divisors (see below), whose sum is σ = 1318618252. Its totient is φ = 1130244192.

The previous prime is 1224431207. The next prime is 1224431233. The reversal of 1224431221 is 1221344221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1221344221 = 1163 ⋅1050167.

It can be written as a sum of positive squares in 2 ways, for example, as 503508721 + 720922500 = 22439^2 + 26850^2 .

It is a cyclic number.

It is not a de Polignac number, because 1224431221 - 2¹⁷ = 1224300149 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1224431192 and 1224431201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1224431821) 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, 47093496 + ... + 47093521.

It is an arithmetic number, because the mean of its divisors is an integer number (329654563).

Almost surely, 2^1224431221 is an apocalyptic number.

It is an amenable number.

1224431221 is a deficient number, since it is larger than the sum of its proper divisors (94187031).

1224431221 is an equidigital number, since it uses as much as digits as its factorization.

1224431221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94187030.

The product of its digits is 768, while the sum is 22.

The square root of 1224431221 is about 34991.8736423187. The cubic root of 1224431221 is about 1069.8218531843.

Adding to 1224431221 its reverse (1221344221), we get a palindrome (2445775442).

The spelling of 1224431221 in words is "one billion, two hundred twenty-four million, four hundred thirty-one thousand, two hundred twenty-one".