420609 has 8 divisors (see below), whose sum is σ = 640960. Its totient is φ = 240336.

The previous prime is 420599. The next prime is 420613. The reversal of 420609 is 906024.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 420609 - 2⁴ = 420593 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 20029 = 420609 / (4 + 2 + 0 + 6 + 0 + 9).

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (420809) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9994 + ... + 10035.

It is an arithmetic number, because the mean of its divisors is an integer number (80120).

2⁴²⁰⁶⁰⁹ is an apocalyptic number.

It is an amenable number.

420609 is a deficient number, since it is larger than the sum of its proper divisors (220351).

420609 is a wasteful number, since it uses less digits than its factorization.

420609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20039.

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 420609 is about 648.5437533428. The cubic root of 420609 is about 74.9249026080.

The spelling of 420609 in words is "four hundred twenty thousand, six hundred nine".