663221009 has 4 divisors (see below), whose sum is σ = 723513840. Its totient is φ = 602928180.

The previous prime is 663220993. The next prime is 663221071. The reversal of 663221009 is 900122366.

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 663221009 - 2⁴ = 663220993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (663221309) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30146399 + ... + 30146420.

It is an arithmetic number, because the mean of its divisors is an integer number (180878460).

Almost surely, 2^663221009 is an apocalyptic number.

It is an amenable number.

663221009 is a deficient number, since it is larger than the sum of its proper divisors (60292831).

663221009 is a wasteful number, since it uses less digits than its factorization.

663221009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60292830.

The product of its (nonzero) digits is 3888, while the sum is 29.

The square root of 663221009 is about 25753.0776607379. The cubic root of 663221009 is about 872.0728347440.

The spelling of 663221009 in words is "six hundred sixty-three million, two hundred twenty-one thousand, nine".