431528821 has 2 divisors, whose sum is σ = 431528822. Its totient is φ = 431528820.

The previous prime is 431528749. The next prime is 431528831. The reversal of 431528821 is 128825134.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 335292721 + 96236100 = 18311^2 + 9810^2 .

It is a cyclic number.

It is not a de Polignac number, because 431528821 - 2⁹ = 431528309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (431528831) 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, 215764410 + 215764411.

It is an arithmetic number, because the mean of its divisors is an integer number (215764411).

Almost surely, 2^431528821 is an apocalyptic number.

It is an amenable number.

431528821 is a deficient number, since it is larger than the sum of its proper divisors (1).

431528821 is an equidigital number, since it uses as much as digits as its factorization.

431528821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15360, while the sum is 34.

The square root of 431528821 is about 20773.2717933406. The cubic root of 431528821 is about 755.6776927608.

The spelling of 431528821 in words is "four hundred thirty-one million, five hundred twenty-eight thousand, eight hundred twenty-one".