421604 has 6 divisors (see below), whose sum is σ = 737814. Its totient is φ = 210800.

The previous prime is 421559. The next prime is 421607. The reversal of 421604 is 406124.

421604 is an esthetic number in base 4, because in such base its adjacent digits differ by 1.

It can be written as a sum of positive squares in only one way, i.e., 220900 + 200704 = 470^2 + 448^2 .

It is not an unprimeable number, because it can be changed into a prime (421607) by changing a digit.

421604 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 as a sum of consecutive naturals, namely, 52697 + ... + 52704.

It is an arithmetic number, because the mean of its divisors is an integer number (122969).

2⁴²¹⁶⁰⁴ is an apocalyptic number.

It is an amenable number.

421604 is a deficient number, since it is larger than the sum of its proper divisors (316210).

421604 is a wasteful number, since it uses less digits than its factorization.

421604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105405 (or 105403 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 421604 is about 649.3104034281. The cubic root of 421604 is about 74.9839373008.

Adding to 421604 its reverse (406124), we get a palindrome (827728).

The spelling of 421604 in words is "four hundred twenty-one thousand, six hundred four".