420845 has 8 divisors (see below), whose sum is σ = 512376. Its totient is φ = 331776.

The previous prime is 420811. The next prime is 420851. The reversal of 420845 is 548024.

It can be written as a sum of positive squares in 4 ways, for example, as 100489 + 320356 = 317^2 + 566^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 420845 - 2⁶ = 420781 is a prime.

It is a super-2 number, since 2×420845² = 354221028050, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 420845.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 212 + ... + 941.

It is an arithmetic number, because the mean of its divisors is an integer number (64047).

2⁴²⁰⁸⁴⁵ is an apocalyptic number.

It is an amenable number.

420845 is a deficient number, since it is larger than the sum of its proper divisors (91531).

420845 is a wasteful number, since it uses less digits than its factorization.

420845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1231.

The product of its (nonzero) digits is 1280, while the sum is 23.

The square root of 420845 is about 648.7256739177. The cubic root of 420845 is about 74.9389132219.

Adding to 420845 its reverse (548024), we get a palindrome (968869).

The spelling of 420845 in words is "four hundred twenty thousand, eight hundred forty-five".