663421 has 8 divisors (see below), whose sum is σ = 741888. Its totient is φ = 588000.

The previous prime is 663409. The next prime is 663437. The reversal of 663421 is 124366.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 663421 - 2¹¹ = 661373 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 663392 and 663401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 285 + ... + 1186.

It is an arithmetic number, because the mean of its divisors is an integer number (92736).

2⁶⁶³⁴²¹ is an apocalyptic number.

It is an amenable number.

663421 is a deficient number, since it is larger than the sum of its proper divisors (78467).

663421 is a wasteful number, since it uses less digits than its factorization.

663421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1523.

The product of its digits is 864, while the sum is 22.

The square root of 663421 is about 814.5065991138. The cubic root of 663421 is about 87.2160482345.

Adding to 663421 its reverse (124366), we get a palindrome (787787).

The spelling of 663421 in words is "six hundred sixty-three thousand, four hundred twenty-one".