431312221 has 2 divisors, whose sum is σ = 431312222. Its totient is φ = 431312220.

The previous prime is 431312201. The next prime is 431312249. The reversal of 431312221 is 122213134.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 305760196 + 125552025 = 17486^2 + 11205^2 .

It is a cyclic number.

It is not a de Polignac number, because 431312221 - 2¹⁹ = 430787933 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (431312201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 215656110 + 215656111.

It is an arithmetic number, because the mean of its divisors is an integer number (215656111).

Almost surely, 2^431312221 is an apocalyptic number.

It is an amenable number.

431312221 is a deficient number, since it is larger than the sum of its proper divisors (1).

431312221 is an equidigital number, since it uses as much as digits as its factorization.

431312221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 288, while the sum is 19.

The square root of 431312221 is about 20768.0577088952. The cubic root of 431312221 is about 755.5512375674.

Adding to 431312221 its reverse (122213134), we get a palindrome (553525355).

The spelling of 431312221 in words is "four hundred thirty-one million, three hundred twelve thousand, two hundred twenty-one".