428660521 has 2 divisors, whose sum is σ = 428660522. Its totient is φ = 428660520.

The previous prime is 428660509. The next prime is 428660563. The reversal of 428660521 is 125066824.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 300155625 + 128504896 = 17325^2 + 11336^2 .

It is a cyclic number.

It is not a de Polignac number, because 428660521 - 2⁵ = 428660489 is a prime.

It is not a weakly prime, because it can be changed into another prime (428660581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 214330260 + 214330261.

It is an arithmetic number, because the mean of its divisors is an integer number (214330261).

Almost surely, 2^428660521 is an apocalyptic number.

It is an amenable number.

428660521 is a deficient number, since it is larger than the sum of its proper divisors (1).

428660521 is an equidigital number, since it uses as much as digits as its factorization.

428660521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23040, while the sum is 34.

The square root of 428660521 is about 20704.1184550321. The cubic root of 428660521 is about 753.9996816271. Note that the first 3 decimals are identical.

The spelling of 428660521 in words is "four hundred twenty-eight million, six hundred sixty thousand, five hundred twenty-one".