421660 has 24 divisors (see below), whose sum is σ = 917280. Its totient is φ = 162624.

The previous prime is 421657. The next prime is 421661. The reversal of 421660 is 66124.

It is a plaindrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421661) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 217 + ... + 943.

It is an arithmetic number, because the mean of its divisors is an integer number (38220).

2⁴²¹⁶⁶⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 421660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (458640).

421660 is an abundant number, since it is smaller than the sum of its proper divisors (495620).

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

421660 is a wasteful number, since it uses less digits than its factorization.

421660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 765 (or 763 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 421660 is about 649.3535246690. The cubic root of 421660 is about 74.9872570943.

Adding to 421660 its reverse (66124), we get a palindrome (487784).

It can be divided in two parts, 421 and 660, that added together give a triangular number (1081 = T₄₆).

The spelling of 421660 in words is "four hundred twenty-one thousand, six hundred sixty".