421780 has 12 divisors (see below), whose sum is σ = 885780. Its totient is φ = 168704.

The previous prime is 421741. The next prime is 421783. The reversal of 421780 is 87124.

It can be written as a sum of positive squares in 2 ways, for example, as 318096 + 103684 = 564^2 + 322^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421783) by changing a digit.

421780 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10525 + ... + 10564.

It is an arithmetic number, because the mean of its divisors is an integer number (73815).

2⁴²¹⁷⁸⁰ is an apocalyptic number.

It is an amenable number.

421780 is an abundant number, since it is smaller than the sum of its proper divisors (464000).

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

421780 is a wasteful number, since it uses less digits than its factorization.

421780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21098 (or 21096 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 421780 is about 649.4459176868. The cubic root of 421780 is about 74.9943699477.

The spelling of 421780 in words is "four hundred twenty-one thousand, seven hundred eighty".