428640409 has 2 divisors, whose sum is σ = 428640410. Its totient is φ = 428640408.

The previous prime is 428640391. The next prime is 428640413. The reversal of 428640409 is 904046824.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 392158809 + 36481600 = 19803^2 + 6040^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-428640409 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (428640439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 214320204 + 214320205.

It is an arithmetic number, because the mean of its divisors is an integer number (214320205).

Almost surely, 2^428640409 is an apocalyptic number.

It is an amenable number.

428640409 is a deficient number, since it is larger than the sum of its proper divisors (1).

428640409 is an equidigital number, since it uses as much as digits as its factorization.

428640409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 55296, while the sum is 37.

The square root of 428640409 is about 20703.6327488680. The cubic root of 428640409 is about 753.9878893284.

The spelling of 428640409 in words is "four hundred twenty-eight million, six hundred forty thousand, four hundred nine".