421667 has 4 divisors (see below), whose sum is σ = 443880. Its totient is φ = 399456.

The previous prime is 421661. The next prime is 421691. The reversal of 421667 is 766124.

It is a semiprime because it is the product of two primes.

It is a de Polignac number, because none of the positive numbers 2^k-421667 is a prime.

It is a Duffinian 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 3 ways as a sum of consecutive naturals, for example, 11078 + ... + 11115.

It is an arithmetic number, because the mean of its divisors is an integer number (110970).

2⁴²¹⁶⁶⁷ is an apocalyptic number.

421667 is a deficient number, since it is larger than the sum of its proper divisors (22213).

421667 is a wasteful number, since it uses less digits than its factorization.

421667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22212.

The product of its digits is 2016, while the sum is 26.

The square root of 421667 is about 649.3589146227. The cubic root of 421667 is about 74.9876720478.

It can be divided in two parts, 4 and 21667, that multiplied together give a palindrome (86668).

The spelling of 421667 in words is "four hundred twenty-one thousand, six hundred sixty-seven".