431345221 has 2 divisors, whose sum is σ = 431345222. Its totient is φ = 431345220.

The previous prime is 431345219. The next prime is 431345237. The reversal of 431345221 is 122543134.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 392594596 + 38750625 = 19814^2 + 6225^2 .

It is a cyclic number.

It is not a de Polignac number, because 431345221 - 2¹ = 431345219 is a prime.

Together with 431345219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (431345281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 215672610 + 215672611.

It is an arithmetic number, because the mean of its divisors is an integer number (215672611).

Almost surely, 2^431345221 is an apocalyptic number.

It is an amenable number.

431345221 is a deficient number, since it is larger than the sum of its proper divisors (1).

431345221 is an equidigital number, since it uses as much as digits as its factorization.

431345221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2880, while the sum is 25.

The square root of 431345221 is about 20768.8521830168. The cubic root of 431345221 is about 755.5705063274.

Adding to 431345221 its reverse (122543134), we get a palindrome (553888355).

The spelling of 431345221 in words is "four hundred thirty-one million, three hundred forty-five thousand, two hundred twenty-one".