421705 has 16 divisors (see below), whose sum is σ = 558720. Its totient is φ = 304128.

The previous prime is 421703. The next prime is 421709. The reversal of 421705 is 507124.

It is a cyclic number.

It is not a de Polignac number, because 421705 - 2¹ = 421703 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (421703) 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 15 ways as a sum of consecutive naturals, for example, 2089 + ... + 2281.

It is an arithmetic number, because the mean of its divisors is an integer number (34920).

2⁴²¹⁷⁰⁵ is an apocalyptic number.

It is an amenable number.

421705 is a deficient number, since it is larger than the sum of its proper divisors (137015).

421705 is a wasteful number, since it uses less digits than its factorization.

421705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240.

The product of its (nonzero) digits is 280, while the sum is 19.

The square root of 421705 is about 649.3881735911. The cubic root of 421705 is about 74.9899245725.

Adding to 421705 its reverse (507124), we get a palindrome (928829).

The spelling of 421705 in words is "four hundred twenty-one thousand, seven hundred five".