421558609 has 2 divisors, whose sum is σ = 421558610. Its totient is φ = 421558608.

The previous prime is 421558607. The next prime is 421558619. The reversal of 421558609 is 906855124.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 297459009 + 124099600 = 17247^2 + 11140^2 .

It is a cyclic number.

It is not a de Polignac number, because 421558609 - 2¹ = 421558607 is a prime.

Together with 421558607, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (421558607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210779304 + 210779305.

It is an arithmetic number, because the mean of its divisors is an integer number (210779305).

Almost surely, 2^421558609 is an apocalyptic number.

It is an amenable number.

421558609 is a deficient number, since it is larger than the sum of its proper divisors (1).

421558609 is an equidigital number, since it uses as much as digits as its factorization.

421558609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 86400, while the sum is 40.

The square root of 421558609 is about 20531.8924846201. The cubic root of 421558609 is about 749.8124621470.

The spelling of 421558609 in words is "four hundred twenty-one million, five hundred fifty-eight thousand, six hundred nine".