421669 has 4 divisors (see below), whose sum is σ = 427680. Its totient is φ = 415660.

The previous prime is 421661. The next prime is 421691. The reversal of 421669 is 966124.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 421669 - 2³ = 421661 is a prime.

It is a super-2 number, since 2×421669² = 355609491122, which contains 22 as substring.

It is a Duffinian number.

421669 is a lucky number.

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 3 ways as a sum of consecutive naturals, for example, 2899 + ... + 3040.

It is an arithmetic number, because the mean of its divisors is an integer number (106920).

2⁴²¹⁶⁶⁹ is an apocalyptic number.

It is an amenable number.

421669 is a deficient number, since it is larger than the sum of its proper divisors (6011).

421669 is an equidigital number, since it uses as much as digits as its factorization.

421669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6010.

The product of its digits is 2592, while the sum is 28.

The square root of 421669 is about 649.3604546013. The cubic root of 421669 is about 74.9877906051.

It can be divided in two parts, 42 and 1669, that added together give a triangular number (1711 = T₅₈).

The spelling of 421669 in words is "four hundred twenty-one thousand, six hundred sixty-nine".