420920 has 32 divisors (see below), whose sum is σ = 1004400. Its totient is φ = 158208.

The previous prime is 420919. The next prime is 420929. The reversal of 420920 is 29024.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (420929) 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, 371 + ... + 989.

2⁴²⁰⁹²⁰ is an apocalyptic number.

420920 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 420920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (502200).

420920 is an abundant number, since it is smaller than the sum of its proper divisors (583480).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

420920 is a wasteful number, since it uses less digits than its factorization.

420920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 647 (or 643 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 420920 is about 648.7834769783. The cubic root of 420920 is about 74.9433646507.

Subtracting from 420920 its sum of digits (17), we obtain a triangular number (420903 = T₉₁₇).

Adding to 420920 its reverse (29024), we get a palindrome (449944).

The spelling of 420920 in words is "four hundred twenty thousand, nine hundred twenty".