421663321 has 4 divisors (see below), whose sum is σ = 421705444. Its totient is φ = 421621200.

The previous prime is 421663313. The next prime is 421663327. The reversal of 421663321 is 123366124.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 99281296 + 322382025 = 9964^2 + 17955^2 .

It is a cyclic number.

It is not a de Polignac number, because 421663321 - 2³ = 421663313 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 421663321.

It is not an unprimeable number, because it can be changed into a prime (421663327) 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, 3511 + ... + 29251.

It is an arithmetic number, because the mean of its divisors is an integer number (105426361).

Almost surely, 2^421663321 is an apocalyptic number.

It is an amenable number.

421663321 is a deficient number, since it is larger than the sum of its proper divisors (42123).

421663321 is a wasteful number, since it uses less digits than its factorization.

421663321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42122.

The product of its digits is 5184, while the sum is 28.

The square root of 421663321 is about 20534.4423104208. The cubic root of 421663321 is about 749.8745396067.

The spelling of 421663321 in words is "four hundred twenty-one million, six hundred sixty-three thousand, three hundred twenty-one".